OBJECTIVE To examine the relation between personality traits and criminal behavior and to determine whether such factors are predictive of future recidivism. METHODS A sample of 481 incarcerated males (mean age = 16 years) completed questionnaires assessing distress and restraint relating to personality characteristics. In addition, official criminological data were gathered from subjects' records. A subsample of 148 juveniles was followed up to 4.5 years after release and examined for rearrests and time out of prison since last incarceration. RESULTS Results indicate a significant association between self-reported levels of distress and restraint and prior criminal behavior as well as behavior during incarceration. Furthermore, of the sample surveyed, 67% were rearrested. Personality traits measured during incarceration were predictive of recidivism rates, above and beyond the effects of such criminological factors as age and number of prior offenses. CONCLUSIONS The results support the view that juvenile delinquents are a heterogeneous population in terms of personality features. These traits have discriminant and predictive validity. Adding personality measures to the assessment of delinquents may further our understanding of how personality influences criminal activity and future recidivism. We may be able to use this understanding to target specific domains of functioning to develop more effective intervention strategies.