Suicide is a major cause of death among inpatients with schizophrenia. However, there are only a limited number of surveys of suicide among such patients, especially in Asia. Therefore, we conducted a multi-institutional survey on suicide death among inpatients with schizophrenia in Japan. We investigated the characteristics of patients with schizophrenia who died by suicide during hospitalization in psychiatric wards, and simultaneously, those of patients with depression. Forty-five suicides of patients with schizophrenia occurred in 27 hospitals, and 46 suicides of patients with depression occurred in 33 hospitals. Hanging was the most common suicide method in both diagnostic groups. More than half of the patients with schizophrenia had histories of suicide attempts, although there was no significant difference in previous suicide attempts or self-harm between both diagnostic groups. Medical staff should confirm whether inpatients with schizophrenia have such histories. In this study, there was no significant difference in characteristics between inpatients with schizophrenia or depression. In order to prevent suicides of patients with schizophrenia during hospitalization, nonspecific suicide attempt prevention needs to be undertaken, such as ensuring comprehension of the general risk factors of suicide among medical staff.