The Prostate Cancer Intervention Versus Observation Trial (PIVOT) is a randomized controlled trial sponsored by the Department of Veterans Affairs and the National Cancer Institute. PIVOT will enroll 2,000 participants from at least 80 Veterans Administration and National Cancer Institute medical centers. The purpose of PIVOT is to determine which of 2 strategies is superior for managing clinically localized prostate cancer (stage T1/T2NXM0) of all histological grades. Patients less than 75 years old will be randomized to either radical prostatectomy with early intervention for disease persistence/recurrence or expectant management with palliative therapy reserved for symptomatic or metastatic disease progression. Participants will be excluded if they have received prior therapy for prostate cancer (except transurethral resection of the prostate) or are judged not to be candidates for radical prostectomy. All patients with newly diagnosed prostate cancer will be recorded on the PIVOT screening log. Registry information will include patient age, race, prostate specific antigen level, clinical stage, histological tumor grade, initial therapy, and vital status. Patients meeting eligibility criteria will watch an information and randomization video tape developed for PIVOT. Participants will be randomized over a 3-year period and followed for a minimum of 12 years. Data collected at followup will include urological symptoms, disease and treatment related morbidity, and disease specific and overall quality of life. Evidence of symptomatic or asymptomatic disease persistence, recurrence or progression will be measured by questionnaire, physical examination, digital rectal examination, prostate specific antigen and annual bone scan. The primary study end point will be all cause mortality. Secondary outcomes will include prostate cancer and treatment specific morbidity and mortality rates, health status, predictors of disease specific outcomes and cost-effectiveness. PIVOT will provide a 90% power to detect a 15% relative decrease in all cause mortality and a 35% relative decrease in prostate cancer specific mortality rate by either treatment strategy.