In this retrospective study demographic and clinical characteristics, personality traits, family psychiatric history and response to treatment were compared in 55 delusional and 40 nondelusional hospitalized patients who met DSM-III criteria for major depression. Male delusional depressives had a greater frequency of delusional ideas at the index episode than female delusionals. Delusional depressives had a greater frequency of family history for alcoholism, a smaller frequency of previous depressive episodes and tended to respond more favorably to treatment with electroconvulsive therapy or tricyclic antidepressants combined with neuroleptics than to antidepressants alone. The findings and the implications arising from them are discussed.