Seen from a societal perspective, the health gains that might result from prostate screening are too uncertain to justify the substantial associated costs and adverse health effects. Clinicians who rely on observational screening studies to justify current screening practices should be aware of the potential biases that render conclusions suspect. Medical history documents numerous cases of medical interventions that appeared reasonable at the time, but ultimately proved worthless and even harmful. Before embarking on an ambitious screening program for prostate cancer, clinicians should demand that five basic criteria are satisfied: (1) that prostate cancer is a significant health burden, (2) that screening can identify localized disease, (3) that tests used in screening programs have acceptable performance among the population being tested, (4) that the potential for cure is greater among patients with screen-detected disease, and (5) that screen-detected patients have improved health outcomes compared with those who are not screened. Randomized trials provide the best methodology for determining the efficacy of screening and treatment. Clinicians are often too quick to credit medical intervention for successful outcomes and blame tumor biology for disease progression. Furthermore, when faced with a decision of administering or withholding therapy, physicians generally wish to err on the side of having done everything possible. Data modeling can provide critical insights concerning these issues using currently available information. Three recently published models suggest that the overall benefit to a population of men screened for prostate cancer can be measured in days of additional time of life gained, not months or years. Furthermore, models suggest that a substantial number of men need to undergo treatment in order to avert a single cancer death. The costs of implementing a screening program are enormous and deflect resources away from alternative uses, such as increased basic science funding to identify a cure for this disease. Therefore, based on the evidence presented, I believe that without more substantial data supporting the efficacy of screening programs, screening for prostate cancer is neither appropriate nor cost-effective.