This study examines risks of violent behavior among 62 offenders in a belgian psychiatric security institution. Two variables were assessed as predictor of the subjects' history of violent behavior recorded in their medical files: (1) subjective classification as "violent" vs "non-violent" by care taking personnel; and (2) scores on Hare's (1991) Revised Psychopathy Checklist (PCL-R). The study assessed also the score of the Michigan Actuarial Scale of Violent Behavior (MARSS) which was not considered as predictor. The PCL-R, the subjective classification and the MARSS were found to be highly intercorrelated. Regression analysis suggest that the PCL-R is a significant predictor of violent behavior. The use of this instrument for the prediction of violent behavior is thus encouraged.