A dismissal without prejudice usually means that a lawsuit or claim may be filed. A dismissal with prejudice, in contrast, typically means that the lawsuit or claim has been fully resolved and cannot be refiled.
Voluntary dismissals with prejudice are, as a matter of practice, often executed by a plaintiff when the parties reach an out-of-court settlement. Under Rule 67.01, “[a] dismissal with prejudice bars the assertion of the same cause of action or claim against the same party.”
The purpose of Rule 67.01 is to extend res judicata principles to cases which are dismissed with prejudice — even when the merits of a lawsuit were not reached. Williams v. Rape, 990 S.W.2d 55, 61 (Mo. Ct. App. 1999); Vilskick v. Standard Insuations, Inc., 926 S.W.2d 499, 501 (Mo. Ct. App. 1996) (“unlike the doctrine of res judicata, application of Rule 67.01 does not require a prior adjudication on the merits”).
Based on these principles, and the legal finality associated with dismissals with prejudice, it is extremely important that they be thoroughly considered before filed.