We investigated the frequency, kind and intensity of aggressive behavior of 494 psychiatric patients at the time of admission. Nine to ten percent of this group showed aggressive behavior. Therefore since 1992 we have a self-defence training for the staff members with the intention of increasing the safety of staff members in situations of assault. Thirty-one staff members who participated in the self-defence training were given the opportunity to evaluate the program by means of self-rating scales. The results show that in their experience the training increases the extent of self-protective behavior and simultaneously decreases the amount of tension in assault-situations. In addition, we evaluated 18 assault-situations, that occurred during the last 2 years. We found out that 5 of 6 staff members who participated in the self-defence-training could protect themselves successfully in contrast to only 2 of 12 staff members who did not participate in this training. Eight of this group were injured during the assault. The results of our investigation indicate that the introduction of self-defence training for staff members is helpful for the safety of staff members working in the field of psychiatry.