This study examined the role of hospital teaching affiliation, third-party payer mix, physician compensation, and case mix on the utilization of inpatient services. Using multivariate analysis with five different utilization measures, we found that: 1) the level of teaching activity and commitment to teaching had no significant effect on the scope of inpatient service utilization; 2) self-pay patients were low utilizers whereas Medicaid patients were high utilizers; 3) inpatient utilization appeared to be lower when physicians were compensated on a salaried basis; and 4) case mix had a significant impact on inpatient utilization.