What are interrogatories?
Interrogatories are written questions that one side in a lawsuit sends to the other as part of discovery. The person who receives them must answer in writing and under oath. In an injury case, they usually ask about your injuries, your doctors, your lost income and how the accident happened.
Last checked November 9, 2026 · Official sources (5)
What do interrogatories look like in an injury case? An example
EXAMPLE ONLY. A month after Sam sues over a motorcycle crash in Phoenix, his lawyer forwards a set of questions from the driver's lawyer. A few of them:
- Describe how the collision happened, in your own words.
- List every doctor or clinic that has treated you in the last ten years, with dates.
- State each injury you claim was caused by the collision.
- State the amount of income you claim to have lost and how you calculated it.
- Identify every person who saw the collision or its aftermath.
Sam's lawyer drafts the answers from his records and Sam's notes. Sam reads every line before signing, because a wrong date or a forgotten earlier injury can be used later to question his honesty.
Why do interrogatories matter for your claim?
Your answers become sworn statements that follow you for the rest of the case. If you list three doctors and the defense finds a fourth, they will ask why. If your deposition later contradicts an answer, that gap can cost you credibility with a jury.
They work in your favor too. Your lawyer can use them to make the other side commit, in writing, to its version of events, its insurance coverage and the witnesses it plans to call.
How many interrogatories can be asked?
| Court | Limit | Deadline to answer |
|---|---|---|
| Federal court | 25, including all discrete subparts | 30 days after service |
| Texas, Level 1 case | 15, not counting questions that only identify documents | Check the rules and any court order |
| California | 35 specially prepared questions as of right, plus official form questions | Check the rules and any court order |
Interrogatories vs. deposition
Both are discovery tools and both are under oath. Interrogatories are written: you get time to look things up, and your lawyer helps word the answers. A deposition is live and spoken, so there is no time to check notes. Interrogatories usually come first, and answering them well makes the deposition easier.
Questions
Do I have to answer interrogatories?
Yes, unless your lawyer makes a valid objection. You must answer each one fully in writing under oath.
Can I say I don't know?
Yes, if it is true, but you are expected to make a reasonable effort to find the answer from records you have.
Who writes my answers?
Usually your lawyer drafts them from your information, and you review and sign. You are responsible for every word.
Find out if you are owed money.
A free case review. $0 upfront. No fee unless you win.
See if I’m owed moneySources (5)
- U.S. Courts, Glossary of Legal Terms, checked 2026-11-09. “Written questions sent by one party in a lawsuit to an opposing party as part of pretrial discovery in civil cases. The party receiving the interrogatories is required to answer them in writing under oath.”
- Fed. R. Civ. P. 33(b)(2), checked 2026-11-09. “The responding party must serve its answers and any objections within 30 days after being served with the interrogatories.”
- Fed. R. Civ. P. 33(a)(1), checked 2026-11-09. “a party may serve on any other party no more than 25 written interrogatories, including all discrete subparts.”
- Tex. R. Civ. P. 190.2, checked 2026-11-09. “Any party may serve on any other party no more than 15 written interrogatories, excluding interrogatories asking a party only to identify or authenticate specific documents.”
- Cal. Civ. Proc. Code § 2030.030(b), checked 2026-11-09. “no party shall, as a matter of right, propound to any other party more than 35 specially prepared interrogatories.”