With the advent of routine prostate-specific antigen (PSA) testing in asymptomatic young men, the number of patients undergoing radical prostatectomy is increasing. Effective therapy for the 30% to 40% of men who recur following radical prostatectomy is essential. Salvage radiation therapy for a rising serum PSA level is an effective therapy for controlling local recurrence. The impact of salvage radiotherapy on disease-free survival is promising, but the guidelines of therapy are not well established. The best candidates for salvage radiotherapy are those with a serum PSA level < 2 ng/mL with no palpable recurrence and complete urinary continence.