Total testosterone and dihydrotestosterone in blood serum as well as free testosterone in saliva were determined by radioimmunoassay in 110 healthy young men. The results were compared with the development of terminal hair on the trunk and limbs, with the disposition to balding and with the disposition to acne. No significant correlations were found between terminal hair development and absolute androgen levels; however, some significant values were observed in the case of the metabolic rate of dihydrotestosterone/testosterone and the proportion of free to total testosterone. The disposition to balding also correlates positively with the latter ratio. Yet the absolute serum androgen concentrations in men with a disposition to balding is lower than in men with no reduction of scalp hair. The widespread assumption that androgen levels are in general elevated in bald-trait men must therefore be rejected. In accordance with this finding, men with a disposition to balding are morphologically (with regard to anthropometric measures) no more masculine than those with good scalp hair growth. When body build and age are taken into consideration, the relations between terminal hair and androgen ratio are also problematical. No relationship could be found between acne and androgens.