Objectives : The critical pathways provide high quality of medical services in a cost-effective manner. To investigate the decrease in length of hospital stay and increase of cost effectiveness by using critical pathways, we compared hospital stay, cost of treatment, and the patient's satisfaction before and after critical pathway use. Methods : We made a critical pathway team, which consisted of obstetric staff members, a resident, two nurses, a pharmacist, two clerical staff members. We made critical pathways for the medical team and patients. A prospective evaluation of a critical pathway for cesarean section was used as a comparison for control patients. Results : The data for 305 patients with a critical pathway were compared to those of 136 control patients. The mean hospital stay is shorter in critical pathway patients than control patients. The cost of treatment decreased and differences between DRG (Diagnosed Related Groups) and cost of treatment increased in critical pathway patients. Conclusions : Using critical pathways in cesarean section decreased the duration of hospital stay and increased cost effectivesess. The critical pathways were useful as a means to minimize cost while increasing patient satisfaction.