The purpose of this study was to evaluate the development of psychosomatic medicine at our university hospital in Istanbul, which has an inpatient capacity of 3.000. Changing patterns of utilization of psychiatric service were analyzed in two 1-year surveys five-year intervals (1998, n=888) - (2003, n=1609). Psychiatric referrals were analyzed with regard to rate of consultation, demographic characteristics, departments making referrals, reasons for referral, psychiatric diagnoses and patterns of psychiatric intervention. Psychiatric consultation request, consultation reply and medical psychiatric examination forms were used. In evaluating the data, consultation rate was seen to have doubled over the five intervening years. Significant changes were also noted in the demographic characteristics of patients (e.g., more men, older mean age). The most prevalent disorders in both groups were depressive disorder and adjustment disorders. Alcohol and substance abuse remained as a small group. The gradual increase in the utilization of psychiatric services can be attributed to service and education-related variables.