OBJECTIVE To compare the resource utilization and clinical outcomes of medical care delivered on general internal medicine inpatient services at teaching and nonteaching services at an academic hospital. METHODS From February to October 2002, 2189 patients admitted to a 450-bed university-affiliated community hospital were assigned either to a resident-staffed teaching service (n = 1637) or to a hospitalist- or clinic-based internist nonteaching service (n = 552). We compared total hospital costs per patient, length of hospital stay (LOS), hospital readmission within 30 days, in-hospital mortality, and costs for pharmacy, laboratory, radiology, and others between teaching and nonteaching services. RESULTS Care on a teaching service was not associated with increased overall patient care costs ($5572 vs. $5576; P = .99), LOS (4.92 days vs. 5.10 days; P = .43), readmission rate (12.3% vs. 10.3%; P = .21), or in-hospital mortality (3.7% vs. 4.5%; P = .40). Mean laboratory and radiology costs were higher on the teaching service, but costs for the pharmacy and for speech therapy, occupational therapy, physical therapy, respiratory therapy, pulmonary function testing, and GI endoscopy procedures were not statistically different between the 2 services, and residents did not order more tests or procedures. Case mix and illness severity, as reflected by the distribution of the most frequent DRGs and mean number of secondary diagnoses per patient and DRG-specific LOS, were similar on the 2 services. CONCLUSIONS At our academic hospital, admission to a general internal medicine teaching service resulted in patient care costs and clinical outcomes comparable to those admitted to a nonteaching service.