When prostatectomy is proposed as treatment for the symptoms of prostatism, the decision to operate should depend on how patients evaluate their symptoms and on objective information about the outcomes. We undertook a health interview study to determine the probabilities for symptom relief, improvement in the quality of life, and complications following surgery and to evaluate patient concern about the symptoms of prostatism. The operation was effective in reducing symptoms: 93% of severely and 79% of moderately symptomatic patients experienced improvement; however, a statistically significant improvement in indices of quality of life occurred only among patients with acute retention or severe symptoms prior to surgery. Short-term complications of varying severity occurred in 24% of patients; in addition, 4% reported persistent incontinence and 5%, impotence. Patients with similar symptoms reported considerable difference in the degree to which they were bothered by their symptoms. The result emphasizes the importance of patient participation in the decision to undergo prostatectomy.