We investigated the extent of aggressiveness of 494 psychiatric patients at the time of admission. This group was divided into two subgroups according to age: 58 patients were more than 65 years old and the remaining 436 patients were less than 65 years old. The two groups were similar as far as kind and frequency of aggressive behaviour against self or others at the time of admission were concerned. There was an important difference in handling the aggressive behaviour as this was significantly easier with the older patients. Furthermore it was possible to describe psychopathological profiles of risk for both allo- and autoaggressive behaviour. Sociodemographic factors could be identified which were linked with the extent of aggressive behaviour by calculating odds ratios.