Interrelations between the intelligence level and delinquent intent of subjects guilty of intentional homicide and exhibiting various mental abnormalities, particularly personality disorder, were studied in Poland. The results showed that 60 percent of the subjects were of average intelligence; these had committed homicide with intent, i.e. their conduct was bent on killing. On the other hand, oligophrenics and mentally deficient subjects usually only meant aggression, the aim or form of which was not precisely determined. These results could indicate a connection between the level of intelligence and intent to kill. However, they should be treated with caution, since other circumstances e.g., the fact that as many as 78 percent of the subjects killed while under the influence of alcohol, could alter the interpretation. In addition, the fact that in as many as in 32 percent of the cases the intent was unclear indicates that Polish law does not cover all the motives and circumstances especially concerning delinquents with psychological abnormalities. Tabular data, and 15 references are included. --in Polish.