Questions about sexual activity were interspersed among other clinical questions in the examination of 101 men between 55 and 86 years of age. All were ambulant patients whose presenting complaints did not per se constitute impediments to sexual activity. Of 51 patients 69 years or less of age, 33 (65%) were potent in the sense of having copulated at least once in the previous year. Of 50 men over 70 years of age, 17 (34%) were potent. There was a general decline with age, but individual differences were marked, and two of the five men who were over 80 years old stated that they were still active, with 10 as the average number of copulations per year. These results are of fundamental importance in assessing the functional results of various types of prostatectomy.