Can You Fail Your Dissertation Defense: Rules, Retakes and Data
Yes, you can fail a dissertation defense. See what named graduate school policies say about failing, second attempts, readiness checks and what pass-rate data exists.
Can you fail your dissertation defense? Yes. Every graduate school policy in this guide allows a committee to record a non-pass, and at the University of Minnesota a failed final oral examination cannot be retaken. Other schools allow a second attempt if the committee agrees.
What we could not find is a national dissertation defense pass rate. Below are the real rules at four US graduate schools, the checks that happen before a defense is scheduled, and what the published US data does and does not measure. In Canada it is spelled “defence”, as on McGill’s oral defence page, and the rules there are set by each university too.
Can you fail your dissertation defense at these four schools
Yes at all four, but what happens next differs. Three allow a second defense in some cases and one does not. The vote rule also differs: unanimous at Ohio State, all but one at Minnesota.
| School | How a fail is recorded | Second attempt |
|---|---|---|
| Ohio State | Unsatisfactory; a pass must be “unanimously affirmative” | Committee decides; no third exam after two fails |
| University of Minnesota | Not passed unless all members, or all but one, vote pass | Students “are not allowed to retake” it |
| Cornell | Fail | Only with the special committee’s approval, at least three months later |
| University of Washington | Unsatisfactory examination | Committee may recommend that the Dean permit a second exam after further study |
At Ohio State, a candidate who fails twice can, with program approval, complete a master’s degree in the same program, or apply for a doctoral degree in a different graduate program. For the full list of results short of a fail, such as a conditional pass, see our guide to dissertation defense outcomes.
Checks that happen before the defense
Some US policies put checks in place before a defense goes ahead. These are formal points where a problem can surface, so they are worth knowing.
Ohio State asks each committee member to approve the complete draft as “of sufficient merit to warrant holding the final oral examination”. At Michigan, Rackham says the candidate should distribute the dissertation to the committee no later than 10 working days before the defense. Members should then send their dissertation evaluations at least 3 working days before it (Rackham policy, section 4.4.8).
These checks do not promise a pass. They do give your committee formal points to raise doubts before the day, which is why the conversations below matter.
A readiness check before you schedule
Ask your advisor these questions before you book a date. Get the answers by email so you can return to them.
- Has every committee member read the full draft, and has anyone raised a concern I have not addressed?
- Does our graduate school require members to approve the draft before the defense, as Ohio State does?
- Which part of the dissertation is a member most likely to push on, and is my answer to it on the page?
- What vote does our policy need to pass, and what happens if one member disagrees?
- If the defense is not passed, does our policy allow a second attempt?
If the answer to the first question is no, wait. A defense date is easier to move than an outcome.
Dissertation defense pass rate: what the data covers
We could not find a national dissertation defense pass rate for the US. The main multi-university data we found, from the Council of Graduate Schools, measures PhD completion and attrition, not defense results.
The CGS Ph.D. Completion Project was a seven-year project that funded 29 US and Canadian research universities to work on completion and attrition. Its page says previous studies suggest that, under highly favorable conditions, no more than three-quarters of doctoral entrants complete their degrees. That figure includes people who leave long before a defense, so it is not a defense pass rate.
For the UK, a 2020 analysis of 14 universities found that just over 96% of candidates who sat a viva passed. We explain where that number comes from and its limits in our guide to the PhD viva pass rate. It describes UK vivas, not US defenses.
Why a defense might not be passed
The policies here set out process rules, not reasons for failing. What they do show is where a non-pass comes from: the committee’s vote on the dissertation and on your examination performance.
Ohio State’s committee votes on “examination performance”, and its second attempts are “only reserved for situations in which the doctoral candidate has met almost every requirement”. Read together, that means the work and the way you defend it both count. Treat the questions in our readiness check as the practical version of that rule.
If you do not pass
Start with the written record, then ask about a second attempt, then think about an appeal. Doing them in that order keeps the most options open.
- Get the decision in writing. Ask the chair for the outcome, the reasons and any conditions. Minnesota already requires committees to give required revisions in writing.
- Ask about a second defense. At Cornell, Ohio State and the University of Washington, the committee’s view on a second attempt is the next step.
- Check the time rules. Cornell requires at least three months between a failed exam and the reexamination.
- Ask about other awards. Ohio State allows a master’s degree in the same program, with program approval, after two fails.
- Consider an appeal only on process. At Cornell, a review after a unanimous fail with no reexamination needs evidence of “a policy violation or procedural error” that materially affected the outcome. Our guide to the dissertation defense appeal covers grounds and deadlines.
If the result is a pass with conditions or changes, the work is different. See our guide to dissertation defense revisions for how to plan them.
If your examination is a UK viva
At UK universities such as Oxford and Imperial, the doctorate is examined at a viva by examiners, and the outcomes include referral and lower awards such as an MPhil. Our guide to what happens if you fail your viva compares the rules at seven UK universities.
What Thesisroom does with this
A committee can only vote on what you show it, on the page and in the room. Thesisroom’s Defense Practice writes questions a committee could ask, each tied to a specific passage or page of your own dissertation. It offers three styles: Practice, Rapid round and Mock panel.
You can answer in writing or out loud. Defense Practice does not write answers or scripts, so the explanation you rehearse stays your own.
Frequently asked questions
Can you fail your dissertation defense?
Yes. Each policy in this guide lets the committee record a non-pass. Minnesota does not allow a retake, while Cornell, Ohio State and the University of Washington allow a second attempt in some cases, decided by or through the committee.
What is the dissertation defense pass rate?
We could not find a national US figure. The Council of Graduate Schools’ Ph.D. Completion Project studied completion and attrition, which includes people who leave before a defense, so it is not a defense pass rate.
Can you retake a failed dissertation defense?
Sometimes. Cornell allows a reexamination with the special committee’s approval, at least three months later. Ohio State’s committee decides on a second exam, but not a third. Minnesota says students are not allowed to retake the final oral examination.
Does one committee member’s vote decide the result?
It can. Ohio State requires a unanimously affirmative decision. Minnesota passes a candidate if all members, or all but one, vote pass. At the University of Washington, a member who disagrees with the majority can send a minority report to the Dean.
What happens after you fail a dissertation defense twice?
At Ohio State, a candidate who fails twice is not allowed another examination. With program approval, they can complete a master’s degree in the same program, or apply to another doctoral program.
Is it “defense” or “defence”?
US English spells it “defense”. Canadian universities such as McGill spell it “defence”. Each university, in either country, sets its own rules on failing and retakes.
Sources
- Ohio State University Graduate School Handbook, section 7: Doctoral degrees
- University of Minnesota: Doctoral degree completion policy
- Cornell University Graduate School: Taking Exams
- University of Washington Graduate School: Final examination (dissertation defense)
- University of Michigan Rackham Graduate School: Policy section 4, doctoral degrees
- Council of Graduate Schools: Ph.D. Completion Project
- McGill University Graduate and Postdoctoral Studies: Oral defence
How this guide was made: Thesisroom drafted this guide with the help of AI writing tools, then checked every fact, figure and source by hand against the references linked above.