The authors analyze the differences in costs between inpatient and outpatient elective surgery, by case mix group*, using the University of Alberta Hospitals Patient Resource Consumption Profile database (PRCP), supplemented with additional data from other agencies. PRCP measures costs for both inpatient and outpatient cases and is linked to the hospital's medical records, so that individual case-costing and detailed cost comparisons can be made. The focus of the comparison is on cost per case, measured in terms of the entire episode of outpatient surgery.