So common is the finding of unsuspected carcinoma of the prostate in aging men that an organized study of the incidence of this neoplasm is indicated. A report on the results of such a study on men who did not seek medical advice spontaneously and the considerations that prompt the study will be presented. From autopsy studies of 100 men over 50 years of age who died of nonurologic diseases, Rich reports a 14% incidence of occult carcinoma of the prostate.1Moore describes a similar necropsy survey that yielded 20.5% incidence of this disease.2Graves and Militzer note bony metastases in 67.5% of 120 hospitalized elderly men with prostatic cancer at the time of the first urologic examination.3Mayer and Roswit state that 95% of patients having prostatic cancer had demonstrable metastases when the diagnosis was first made.4Many other clinical publications contain discussions of the