The aim of the present study was to examine the relationships between suicidal ideation or suicidal attempts and severity of depression, presence of personality disorders, and sociodemographic factors in a population of depressed in-patients. A total of 338 adult depressed psychiatric in-patients were examined and classified according to DSM-III criteria as having major depression with or without melancholic or psychotic features, adjustment disorder with depressed mood or dysthymic disorder. Scores on the Hamilton Depression Rating Scale (HDRS), Beck Depression Inventory (BDI) and Zung Self-Rating Depression and Anxiety Scales (SDS and SAS) were measured. We found that suicidal ideation was significantly related to severity of depression (according to the HDRS and all self-rating scales), a lower global assessment of functioning the year before hospitalization, and previous psychiatric hospitalizations. The items with the strongest predictive value for suicidal ideation were hopelessness, depressed mood, feelings of guilt, loss of interest and low self-esteem. These symptoms predicted 43% of the variance in suicidal ideation. None of the above predictors of suicidal ideation was related to suicidal attempts. Depressed patients with a personality disorder attempted significantly more suicidal attempts and showed more suicidal ideation than depressed patients without personality disorder. No significant correlations were found between suicidal ideation or suicide attempts and gender, marital status, employment status or psychosocial stressors during the previous 6 months.