One hundred three ambulatory elderly men had serum free testosterone (FT) assessed as part of a study of bone loss. The FT was analyzed using radioimmunoassay. Each participant was questioned regarding the presence of erections adequate for sexual activity and the presence of sexual desire. Each was examined for decreased axillary and pubic hair. A FT of less than 9.0 pg/mL was found in eight subjects. The sensitivity of the clinical predictors as an indicator of a low FT value ranged from 43% to 86%, while positive predictive value ranged from 12% to 19%. The abnormal clinical signs and symptoms investigated in this study obviously have mechanisms in addition to hypogonadism. A history of adequate erections ruled out a low FT value in all but 1 of 44 cases.