Object: Although the relationship of psychiatric diseases and crime is getting more and more attention in recent years, research and literature on forensic cases are inadequate in our country. We investigated the psychiatric diagnosis of cases and the relationship between diagnosis and crime in patients referred to Bakırköy State Hospital for Psychiatric and Neurological Diseases, which, as a hospital represents an important accumilation of experience on medical expert witness duty and compulsory treatment of forensic cases

Method: Medical charts of 1831 cases, referred by courts for assesment of criminal responsibility according to Act 46 of Turkish Penalty Law (TPL) and were given a final report by the medical board of experts, were investigated retrospectively and psychiatric diagnosis were cathegorized according to DSM-III-R.

Conclusion: 48.9 of the cases (n=895) were considered as not having criminal responsibility according to Act 46 ofTPL, 6.7 % (n=123) were considered as having only partial criminal responsibility according to Act 47, and the remaining cases (43.5 %, n=796) were considered as possessing full criminal responsibility. When cases not possessing criminal responsibility were assesed by their axis 1 of their psychiatric diagnosis, 32.8 % (n=294) were diagnosed as having schizophrenia, 26.4 (n=236) mood disorders, 14.3 % (n=128) delusional disorders, 9.9 % (n=89) PD NOS [psychotic disorder not otherwise specified], 5.5 % (n=49) mental disorders due to a general medical condition, 2.5 % (n=22) psychotic disorder due to substance abuse and 2.5 % (n=22) other psychiatric diagnosis. Chronic and progressive psychotic disorders were found to be involved in more violent crimes and often these crimes were found not to be organized.