We assessed the 1-year charges in the group of patients undergoing radical prostatectomy and the changes in hospital costs and resource use following implementation of a clinical care path. A total of 69 consecutive men treated with radical prostatectomy for clinically localized prostate cancer were enrolled in the study. Hospital and outpatient records were analyzed for each patient in regard to preoperative, operative and postoperative charges of a 12-month period. Parameters included number of encounters, diagnostic and therapeutic interventions, hospitalization and operative charges, and follow-up visits, diagnostic tests and interventions for 1 year. The mean first-year cost of treatment with radical prostatectomy for localized prostate cancer was 144 x 10(4) yen. The increases in the first-year cost with higher prostate specific antigen (PSA) level for the diagnosis level appeared to primarily be associated with increased inpatient resource use and greater use of hormonal therapy. Length of the stay in a hospital significantly influenced the first-year cost. After implementation of the radical prostatectomy care path hospital costs decreased by 30% (66 x 10(4) yen vs 46 x 10(4) yen), total costs decreased 40% (190 x 10(4) yen vs 113 x 10(4) yen) and length of hospital stay decreased by 56% (37.0 vs 16.6). The first-year costs with radical prostatectomy are influenced greatly by the hormonal therapy and the number of hospital days. By standardizing preoperative and postoperative management for patients undergoing radical prostatectomy, significant savings can be achieved toward shorter hospital stays and lower hospital costs.