A preliminary investigation of the impact of pretrial evaluations of trial competence and legal insanity, and the variables that mediate case outcomes is reported. Twenty-four percent of defendants evaluated as incompetent to stand trial were found competent by the court or were tried without the question of competence being adjudicated. Charges were dropped in more than half of the cases in which an evaluator considered a defendant incompetent, most frequently in cases involving misdemeanor charges and/or the clinician considered it unlikely that the defendant could be restored to competence. One third of defendants considered to meet criteria for legal insanity subsequently were acquitted NGRI; more than half did not present an insanity defense and were ultimately convicted or plea bargained a guilty verdict. The defendants considered to meet the criteria for legal insanity were more likely than their mentally ill but not insane counterparts to have treatment ordered in lieu of incarceration. The defendant's age and race and the evaluator's professional discipline were unrelated to case outcome.