BACKGROUND There is little if any research on the explicit contents delivered by patients in the first minutes of a psychiatric interview. METHODS In order to study the impact of the first minutes of a psychiatric interview on final diagnosis, we gathered information from the speech during the first 5 min in 162 new psychiatric patients with a checklist including symptoms extracted from the SCAN interview. RESULTS The area reported most frequently was life events (51.2%). The average of psychiatric symptoms cited was 2.3. An initial suspected diagnosis was done in 126 patients, and in 73 patients (57.9% of those with a suspected diagnosis, 45.1% of the total sample) the initial diagnosis was coincident with the final diagnosis. The initial clinical impression was more accurate in adjustment and 'neurotic' disorders, and less in mood disorders. Those patients who cited more symptoms received a less accurate initial diagnosis. CONCLUSION Psychiatric patients spontaneously report a low number of symptoms. The accuracy of psychiatric diagnosis in the first minutes of an interview is unacceptably low. However, the role of short psychiatric interviewing as a screening method deserves to be further investigated.