The patients with brain tumors are quite rare in forensic-psychiatric practice. The authors observed only 21 cases during 25 years (that is 0.05% from all the persons subjected to the forensic-psychiatric examination). The tumors were revealed in 11 patients during examination; 10 patients underwent forensic-psychiatric examination after operation for brain tumor. There were different mental disturbances of various degree in such patients: disorders of memory, emotional instability, impulsivity, disorders of consciousness, phenomena typical for epileptiform syndrome, and other disorders. 16 patients were characterised as irresponsible ones. The supervision of neurologist and psychiatrist was recommended in all cases.