Vancouver citation style is a numbered referencing system used mainly in medicine and the biomedical sciences. Instead of an author’s name in the sentence, you place a number in the text, and that number points to a full source entry in a numbered reference list at the end of the paper. This guide covers how the numbering works, how to format the reference list, and the mistakes students make most often.
What Is Vancouver Style?
Vancouver style is a numbered citation system used mainly in medicine, nursing, and the health sciences. Sources are numbered in the order they first appear in the text, and each number matches a full entry in a numbered reference list at the end of the paper. This citation-sequence approach is why Vancouver style looks so different from name-based systems like APA or MLA.
The style takes its name from a 1978 meeting of medical journal editors in Vancouver, British Columbia, known as the Vancouver Group. Their agreement became the ICMJE Recommendations, and Vancouver style is now the default citation format for journals indexed in MEDLINE and PubMed, as well as the required style for most nursing, medicine, dentistry, and pharmacy programs.
How In-Text Citations Work in Vancouver Style
Every time you use a source, you assign it a number. The first source you cite becomes 1, the second becomes 2, and so on. If you cite the same source again later in the paper, you reuse its original number rather than assigning a new one.
Numbers can appear in three accepted formats, depending on your instructor’s or journal’s preference: superscript1, in parentheses (1), or in square brackets [1]. Whichever format you choose, use it consistently throughout the paper.
Correct: Recent analysis suggests that regular exercise reduces cardiovascular risk in adults over 40.3 A separate cohort study found similar results in younger patients.3
The same source (a cohort study cited twice) keeps the number 3 both times, because it was the third source introduced in the paper.
Incorrect: Recent analysis suggests that regular exercise reduces cardiovascular risk in adults over 40.3 A separate cohort study found similar results in younger patients.7
Assigning a new number (7) to a source you already cited as 3 breaks the sequence and misdirects the reader to the wrong reference list entry.
For multiple sources in one place, separate the numbers with a comma and no space (1,2), or use a hyphen to show a consecutive range (3-5). When quoting directly, add the page number after the citation number, preceded by “p”: Smith1(p42) found that… See our guide on introducing quotations for more on blending quoted material into your own sentences.
Citation numbers can sit either before or after a sentence’s closing punctuation, and both placements appear across published style manuals. Placing the number after the period keeps the sentence visually uninterrupted, which is why many universities recommend it for student papers, while some scientific journals place the number before the period so it reads as part of the clause it supports. Whichever placement you choose, apply it the same way every time.
General Rules for the Reference List
Every source you cite in the text needs a matching numbered entry in the reference list, listed in the same numerical order the sources first appear. Each entry follows a strict, fixed sequence of elements, author names, title, journal or publisher, and date, and the exact elements change slightly depending on whether you’re citing a journal article, a book, or a website.
According to Citing Medicine, the NLM’s official style manual for Vancouver-style referencing, the six rules below apply across nearly every source type, whether the source itself is print or online.
| Element | Rule |
|---|---|
| Author names | Surname first, followed by initials with no periods or spaces between them (e.g. Smith JA). List names in the order they appear on the source. |
| Multiple authors | Separate each author with a comma. Many instructors ask for the first six authors followed by “et al.” when there are seven or more, though some current guides list every author. Check your assignment’s specific rule. |
| Titles | Use sentence case (capitalize only the first word and proper nouns) for article and book titles, followed by a period. |
| Journal names | Abbreviate journal titles using standard NLM abbreviations rather than spelling them out in full. |
| Publication year | Use the four-digit year, followed by a semicolon for journal articles or a period for books. |
| Page ranges | Hyphenate page ranges and drop repeated digits (452-468 becomes 452-68). |
How to Cite Common Source Types in Vancouver Style
The exact order of elements changes depending on what you’re citing, whether it’s a journal article, a book, a book chapter, or a website. Vancouver style is stricter about this order than author-date systems like APA, because reviewers, citation-checking software, and journal editors expect each element in a fixed sequence. The table below covers the four source types students cite most often, with a full worked example for each.
| Source type | Format | Example |
|---|---|---|
| Journal article | Author(s). Title. Journal abbreviation. Year;Volume(Issue):Pages. | Marks MA, Chaturvedi AK. Association of marijuana smoking with oropharyngeal cancer. Cancer Epidemiol Biomarkers Prev. 2014;23(1):160-71. |
| Book | Author(s). Title. Edition. Place of publication: Publisher; Year. | Malamed SF. Handbook of local anesthesia. 7th ed. St. Louis: Elsevier; 2020. |
| Book chapter | Chapter author(s). Chapter title. In: Editor(s), editors. Book title. Edition. Place: Publisher; Year. Page range. | Forrest JL, Miller SA. Evidence-based decision making. In: Bowen DM, Pieren JA, editors. Dental hygiene theory and practice. 5th ed. Maryland Heights: Elsevier; 2020. p. 25-33. |
| Website | Author or organization. Title [Internet]. Place: Publisher; Year [cited Year Month Day]. Available from: URL | Statistics Canada. The Canadian population in 2011 [Internet]. Ottawa: Statistics Canada; 2015 [cited 2016 Dec 30]. Available from: https://www12.statcan.gc.ca |
Some nursing and dental hygiene programs use a modified version of Vancouver style with small formatting differences. Always compare your draft against the citation guide your instructor, department, library, or target journal provides before submitting.
Vancouver vs. AMA Style
AMA style, published by the American Medical Association, is built directly on top of Vancouver style. Both use numbered in-text citations and a numbered reference list in order of first appearance, so a citation formatted correctly in one system looks almost identical in the other. The differences are mostly cosmetic, covering italics, superscript placement, and title capitalization, and AMA doubles as a full writing style guide beyond just references.
If a journal or professor asks for “AMA” instead of “Vancouver,” the underlying numbering logic covered in this guide still applies.
In practice, most instructors care less about which historical convention you follow and more about consistency: pick a single author-list rule and a single number-placement rule for the whole paper, and don’t switch between them halfway through. When in doubt, match whatever example paper or template your course or journal has already provided.
Common Vancouver Style Mistakes to Avoid
Most Vancouver style errors come from applying rules meant for author-date systems like APA. The table below lists the five mistakes that show up most often in student papers, along with why each one causes problems and how to fix it.
| Mistake | Why it’s a problem | Fix |
|---|---|---|
| Numbering sources alphabetically | Vancouver style numbers by order of first appearance, not by author surname. | Assign each source a number the first time it’s mentioned in the text. |
| Spelling out full journal titles | Vancouver style expects standardized abbreviations, not full names. | Search the NLM’s free online journal abbreviation database (linked in the NLM’s journal abbreviation rules) before finalizing your reference list. |
| Giving a cited source a new number on reuse | This breaks the reference list mapping and misdirects the reader. | Always reuse the number the source was first assigned. |
| Mixing citation number styles | Switching between superscript, brackets, and parentheses looks inconsistent. | Pick one number format and use it for the entire paper. |
| Skipping the “et al.” or full author list rule | Author-list length rules vary by publisher and are easy to get wrong. | Confirm the author cutoff your instructor or journal expects before submitting. |
Vancouver Style Resources
These free resources are useful once you move beyond the basics covered here:
- Citing Medicine (NLM)
- ICMJE Recommendations
- NLM journal abbreviations
- EssayReply Citation Generator
For a quick, automated first draft of any reference, try the EssayReply Citation Generator, then check the output against the rules above before submitting.
Related Citation Guides
Looking for a different citation format? Visit the main citation guide hub for APA, MLA, Chicago, and more.
Frequently Asked Questions
Is Vancouver style the same as AMA style?
They’re closely related but not identical. AMA style is built on Vancouver’s numbered citation-sequence system, so the core logic is the same, but AMA adds its own rules for formatting, italics, and capitalization, plus general writing guidance that goes beyond citations. If your professor or journal specifies AMA, follow AMA’s exact formatting rather than a generic Vancouver example.
Should I use superscript or brackets for Vancouver in-text citations?
Either is acceptable in Vancouver style, along with parentheses. Superscript numbers are common in journal articles because they don’t interrupt the sentence, while brackets or parentheses are often preferred in student papers for readability. Check your instructor’s or journal’s guidelines, and then use the same format for every citation in the paper.
How many authors do I list before using “et al.” in Vancouver style?
This varies by publisher. Many instructors and journals still follow the older convention of listing the first six authors followed by “et al.” when a source has seven or more contributors, while the current edition of Citing Medicine lists every author regardless of how many there are. Confirm which rule your nursing, medicine, or pharmacy program follows before finalizing your reference list.
What number do I use if I cite the same source twice?
Reuse the number the source was assigned the first time it appeared in your paper. Vancouver style numbers sources by order of first appearance, not by how many times they’re cited, so a source you introduce as reference 4 stays reference 4 every time you mention it again.
Do reference managers like Zotero or EndNote support Vancouver style?
Yes. Zotero, EndNote, and Mendeley all include a built-in Vancouver style (sometimes listed as “Vancouver” or “ICMJE”) that formats your reference list and in-text numbers automatically. It’s still worth spot-checking a few entries against the rules in this guide, since reference managers occasionally mis-format journal abbreviations or author initials.
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Terry is a Chicago-based writer and editor who creates practical, student-friendly guides on essay writing, research, and citation styles (APA, MLA, and Chicago). He’s spent 15+ years editing educational content and building clear examples that help readers apply rules without guessing. When he’s not revising drafts, he’s usually turning messy notes into clean outlines and hunting down the one detail everyone skips.