Background In 2002, we reported the initial results of a trial comparing radical prostatectomy with watchful waiting in the management of early prostate cancer. After three more years of follow-up.. we report estimated 10-year results. Methods: From October 1989 through February 1999, 695 men with early prostate cancer (mean age, 64.7 years) were randomly assigned to radical prostatectomy (34 7 men) or watchful waiting (348 men). The follow-up was complete through 200, with blinded evaluation of the causes of death. The primary end point was death due to prostate cancer; the secondary end points were death from any cause, metastasis, and local progression, Results: During a median of 8.2 years of follow-up, 83 men in the surgery group and 106 men in the watchful-waiting group died (P=0.04). In 30 of the 347 men assigned to surgery (8.6 percent) and 50 of the 348 men assigned to watchful waiting (14.4 percent), death was due to prostate cancer. The difference in the cumulative incidence of death due to prostate cancer increased from 2.0 percentage points after 5 years to 5.3 percentage points after 10 years, for a relative risk of 0.56 (95 percent confidence interval, 0.36 to 0.88; P=0.01 by Gray's test). For distant metastasis, the corresponding increase was from 1.7 to 10.2 percentage points for a relative risk in the surgery group of 0.60 (95 percent confidence interval, 0.42 to 0.86; P=0.004 by Gray's test), and for local progression, the increase was from, 19.1 to 25.1 percentage points, for a relative risk of 0.33 (95 percent confidence interval, 0.25 to 0.44; P < 0.001 by Gray's test). Conclusions: Radical prostatectomy reduces disease-specific mortality, overall mortality and the risks of metastasis and local progression. The absolute reduction in the risk of death after 10 years is small, but the reductions in the risks of melastasis and local tumor progression are substantial.