With a lack of data from randomized trials, the optimal management of men with nonmetastatic prostate carcinoma is controversial. The authors sought to define the outcomes of three common strategies for managing patients with nonmetastatic prostate carcinoma: expectant management, radiotherapy, and radical prostatectomy. The authors conducted a retrospective cohort study with standardized collection of key prognostic data, including centralized assignment of Gleason grades from original biopsy specimens. Participants included all Connecticut hospitals (the expectant management cohort) and three academic medical centers in other states (the radiotherapy and surgery cohorts). Two thousand three hundred eleven consecutive men ages 55–74 years who were diagnosed during 1971–1984 with nonmetastatic prostate carcinoma and were treated at the participating sites were included. Kaplan–Meier estimates with 95% confidence intervals (95% CI) of overall survival at 10 years for each cohort were as follows: expectant management cohort, 42% of patients (95% CI, 38–46%); radiotherapy cohort, 52% of patients (95% CI, 46–58%); and radical prostatectomy cohort, 69% of patients (95% CI, 67–71%); for disease specific mortality, the estimates were as follows: expectant management cohort, 75% of patients (95% CI, 71–79%); radiotherapy cohort, 67% of patients (95% CI, 61–73%); and radical prostatectomy cohort, 86% of patients (95% CI, 84–88%). There were large differences in distributions of important prognostic factors among men in the different treatment groups. These data provide precise estimates of the outcomes of patients who have been treated with different modalities for nonmetastatic prostate carcinoma in the recent past. Direct comparisons of outcomes between treatment groups are inadvisable because of the different characteristics of patients who select these alternative management strategies. Cancer 2001;91:2302–14.