The present study combines four factors: an initial research interview, a blind follow-up of the patients seen initially, the use of specified diagnostic criteria, and the application of these techniques to a psychiatric emergency room population of 314 patients. Follow-up studies were done in 299 patients (95%) a mean of 18.2 months after the initial interview. The patients were described diagnostically and demographically. There were three more common diagnoses: affective disorder, alcoholism, and antisocial personality. There were ten additional less common diagnoses, as well as an undiagnosed group and a group without diagnosis. There were single diagnoses in 190 patients and multiple diagnoses in the remaining 124 patients. Three diagnoses or less per patient were not uncommon; more than three diagnoses per patient were uncommon. Diagnoses of affective disorder, alcoholism, and antisocial personality occurred in 64% of the total number of diagnoses. The remainder of the diagnoses occurred in 36%. Prompt hospitalization occurred in 14% of the total sample.