Investigation of the development in the incidence of suicide among psychiatric patients is reviewed and it is concluded that the majority of investigations have demonstrated an increasing suicide rate even when the increasing numbers of admissions and discharges are taken into consideration. It is concluded that altered circumstances for psychiatric patients have played a part in relation to the increase in the suicide rate. Investigation of the suicide rates related to diagnoses suggest that manic-depressive patients, alcoholics and schizophrenics have the highest suicide rates. In investigations of patients who died from suicide as compared with patients who did not die from suicide but who were otherwise comparable, it appears that unmarried status, male sex and previous attempted suicide and suicidal thoughts are more frequently correlated with subsequent suicide. Medical audit in connection with suicide among psychiatric patients is discussed as a possible method of improving the training and competence of psychiatric staff in relation to suicidal behaviour.