Good question. The answer varies depending on what you are suing for and what the facts of the case are. If you have specific questions, consult an attorney directly. Generally, you have the time periods listed below to file a lawsuit before a statute of limitations may prohibit you from ever recovering, even if you have a really good claim:
Section 95 of Title 12 of the Oklahoma Statutes provides that a civil action other than for the recovery of real property can only be brought within the following periods of time after the cause of action has accrued (the time you can first sue):
(1) within 5 years for an action upon any contract, agreement or promise in writing;
(2) within 3 years for an action upon a contract express or implied not in writing; an action upon a liability created by statute other than a forfeiture or penalty; and an action on a foreign judgment;
(3) within 2 years for an action for trespass upon real property; an action for taking, detaining or injuring personal property, including actions for the specific recovery of personal property; an action for injury to the rights of another, not arising on contract, and not hereinafter enumerated; an action for relief on the ground of fraud—the cause of action in such case shall not be deemed to have accrued until the discovery of the fraud;
(4) within one year for an action for liable, slander, assault, battery, malicious prosecution, or false imprisonment; an action upon a statute for penalty or forfeiture, except where the stature imposing it prescribes a different limitation.
Since there are so many facts and issues that can alter these limitations, I recommend that you talk with an attorney as soon as possible if you have questions.