Can You Cite a Preprint in Your Thesis? When It Works and When It Does Not

The short answer, with three conditions

Can you cite a preprint in a thesis? Yes, in most fields, under three conditions. The preprint must be relevant to a claim your argument needs. It must be clearly marked as a preprint in the citation. And the reader must be able to see, from the citation itself, that the paper has not yet been peer-reviewed at the time of your writing.

Preprint citation is more common now than a decade ago. arXiv (physics, mathematics, computer science) has hosted preprints since 1991. bioRxiv (biology, since 2013) and medRxiv (medicine, since 2019) have made preprint-first publication routine in the life sciences. SSRN (social sciences and economics, since 1994) plays a similar role in its fields. Preprint citation is standard practice in these disciplines; the practice varies elsewhere.

Why the caveats matter

A preprint has not been peer reviewed. It has been posted to a public server, given a stable URL and often a DOI, and made available for the field to read and comment on. Some preprints are later published in peer-reviewed journals largely unchanged. Others are revised substantially before publication. Some never appear in journals at all, because the review process caught something wrong.

Citing a preprint means citing work at a specific stage. If the argument changes in the peer-reviewed version, and your thesis quotes the preprint, the quotation may no longer be accurate. Examiners check for this in fields where preprint use is common, especially when the citation is doing heavy work in the argument (Park, 2003). The same caution applies to a paper you only know through another author’s citation: cite a secondary source in APA as such, or find the original.

Which fields accept preprint citations

Acceptance varies more by field than by institution.

Physics, mathematics, computer science: preprint citations are routine and expected. Papers on arXiv are treated as legitimate citations for most purposes, and many arXiv preprints are cited more heavily than the journal versions that follow. The convention is to cite the arXiv ID or DOI alongside the journal version if one exists.

Biology and life sciences: bioRxiv and medRxiv citations are increasingly accepted, especially for recent findings the peer-reviewed literature has not caught up with. Many journals now require or encourage authors to post preprints. Doctoral candidates in these fields cite preprints regularly.

Social sciences and economics: SSRN and RePEc have long served as preprint (and working paper) archives. Working-paper citation has been standard in economics for decades. Sociology and political science are more mixed; check your discipline’s convention.

Humanities: preprint culture is thinner. Most citations remain to peer-reviewed journal articles, chapters, and monographs. Where preprint citation appears, it usually flags a specific reason (the peer-reviewed version is inaccessible; the preprint is the only version that contains a specific figure).

Medicine and clinical fields: preprint citation grew sharply during the 2020s and is now common in research-oriented dissertations, though clinical guidelines and standard-of-care claims still rely on peer-reviewed sources.

The three conditions in detail

Condition 1: Mark the citation as a preprint. The reference list entry should identify the server, the preprint ID or DOI, and the deposit date. Example: “Author, A. (2025). Title of the paper. arXiv preprint. https://doi.org/10.48550/arXiv.2501.12345.” The reader can see immediately that this is a preprint and not a peer-reviewed article. Software and code need their own format; see how to cite software in APA 7.

Condition 2: Verify the preprint still exists as cited. Preprints can be withdrawn, revised, or replaced. A preprint you cited in 2024 may have been withdrawn by 2026. Resolve the DOI to check the current version. If the version has changed, either update your citation to the current version or note the specific version you cited.

Condition 3: Note the specific version. Preprint servers use versioning (v1, v2, v3, ...). Citing without a version means citing whatever the current version is at the time the reader looks. If your argument depends on something the current version has removed, the citation reads as inaccurate. State the version: “arXiv:2501.12345v1” for the first version, “v2” for the second, and so on.

When to swap a preprint for the peer-reviewed version

If the preprint you cited has been published in a peer-reviewed journal, and the argument is unchanged, update the citation to the journal version. Some fields prefer this once available; others allow either. The check is whether the peer-reviewed version supports the claim your argument depends on. If yes, cite the peer-reviewed version. If the preprint contains something the journal version dropped, keep the preprint citation and note why. When you swap, check the journal is not predatory before the new citation goes in.

Running this check across a whole bibliography during writing years is unrealistic without help. Papers move from preprint to publication throughout the year, and reference managers do not track the transition. That holds for Zotero and for other reference managers. Thesisroom’s citation guard can flag preprint citations where a peer-reviewed version now exists, so the swap is targeted rather than manual.

When examiners look at preprint citations closely

Examiners tend to check preprint citations more closely than journal citations, for one reason: preprints are the citations most likely to have changed since the writing. If a load-bearing claim rests on a preprint, expect the panel to ask what has happened to it since. A candidate who can say “the preprint has since been published in Journal Name with the finding intact” is answering well. A candidate who does not know the current status of the preprint is showing that verification stopped at citation.

This is why the Thesisroom method treats bibliography verification as a whole-degree seat. Preprints saved in year one need re-checking in year three, because they may have moved. The same applies to anything an AI tool suggested; see AI tools citing retracted papers.

What Thesisroom does with this

Thesisroom’s citation guard verifies preprint citations against Crossref, arXiv, and bioRxiv metadata where available. Entries where the preprint has been withdrawn, replaced, or peer-reviewed are surfaced, so the writer can decide whether to update. Source Finder returns peer-reviewed alternatives when a preprint has since been published, or when a preprint is doing work in the argument that a peer-reviewed source could do better.

None of this substitutes for the writer’s judgement about which version to cite. It removes the manual re-check step, which is what actually causes preprint citations to go stale.

Frequently asked questions

Is citing a preprint the same as citing a peer-reviewed paper?

No. A preprint has not been peer reviewed at the time of citation, and the citation should make that visible to the reader. Preprints can be legitimate sources for a specific claim, especially for recent findings, but they carry different weight than peer-reviewed sources and should be presented as such.

Which fields prefer or allow preprint citations?

Physics, mathematics, computer science (arXiv), biology (bioRxiv), medicine (medRxiv), and economics (SSRN, RePEc) all have established preprint cultures. Humanities and clinical medicine are more mixed. Check your discipline’s convention and your programme’s guidance before relying on preprints in a load-bearing citation.

What happens if the preprint I cited is withdrawn?

Treat it like a retraction. Check the preprint server for the withdrawal notice and the reason. If the withdrawal was for a reason that affects your argument, remove the citation and either replace it or reframe the claim. If the withdrawal was for a reason that does not affect your argument (a duplicate submission, a merged version), note the withdrawal and cite the current version.

Do I need to cite the specific version of a preprint?

Yes, if the version matters for the claim you are making. Preprint servers use versioning (v1, v2, ...) and each version can differ. Citing “arXiv:2501.12345” without a version means citing whatever the current version is at the time the reader looks, which is unstable. Cite “arXiv:2501.12345v2” to be specific.

Should I always swap a preprint for the peer-reviewed version if it exists?

Usually yes, unless the preprint contains something the peer-reviewed version dropped. If the argument depends on that specific content, cite the preprint version and note why. If the argument works either way, the peer-reviewed version is the safer citation because it carries the additional weight of peer review.

Can Thesisroom check my preprint citations?

Citation Guard verifies preprints against Crossref, arXiv, and bioRxiv metadata where available. It flags entries where the preprint has been withdrawn or where a peer-reviewed version now exists that supersedes the citation. The writer decides whether to update. This is the specific gap that reference managers do not fill, because they do not re-verify.

One takeaway before you close this tab

Yes, you can cite a preprint in a thesis. The three conditions are: mark it as a preprint in the reference list, verify it still exists as cited, and note the specific version. When you want automatic re-checking so a preprint you cited in year one is flagged if it has moved by year three, Thesisroom’s citation guard is where the check lives.

References

Park, C. (2003). Levelling the Playing Field: Towards Best Practice in the Doctoral Viva. Higher Education Review, 36(1), 47-67.