The high comorbidity of medical and psychiatric diagnoses in the general hospital population requires collaboration between various medical fields to provide comprehensive health care. This study aims to find the rate of psychiatric consultations, their timing and overall diagnostic trend in comparison to previous studies. Tehran University of Medical Sciences has got an active psychiatric consultation-liaison service which includes services provided by four faculty psychiatrists (two full-time and two part-time). This study was done in two general hospitals by simple sampling in available cases. For each consultation, a board-certified faculty psychiatrist conducted a clinical evaluation based on DSM-IV-TR. Other than psychiatric diagnoses, socio-demographic variables, relative consultation rates, reasons for referral, medical diagnoses and the time stay after admission were assessed. Among 503 patients who were visited by the consultation-liaison service, there were 54.3% female with mean age of 39.8 years. In 90.1% of consultations, at least one DSM-IV-TR diagnosis was made. The most frequent diagnosis groups were mood disorder (43.5%), adjustment disorder (10.9%) and cognitive disorder (7.6%). In about 10.9% of the consultations, multiple psychiatric diagnoses were made. The mean length of hospital stay before the consultation was 12.56 days (range=1-90, SD=13). Based on our findings, the mood and cognitive disorders still remain major foci of consultation-liaison practice in general hospitals; however our findings showed high rate of adjustment disorders diagnosis and ambiguous request for psychiatric consultation which need more interdisciplinary interaction.