To elucidate the relationship between body build, androgens, and transsexual gender identity, anthropometric measurements were assessed in 15 hormonally untreated female-to-male-transsexuals (FMT). Nineteen healthy women (CF) (X = 22 years; 2 months), and 21 healthy men (CM) (X = 23; 7) were enrolled as controls. Baseline levels of testosterone (T; ng/dl), androstenedione (A4; ng/dl), dehydroepiandrosterone sulfate (DHEAS; ng/ml), and sex-hormone binding globulin (SHBG; microgram/ml) were assessed in 12 FMT, 15 CF, and in all CM. No control was under hormonal medication (including contraceptives). Absolute measurements in FMT were in accordance with their biological sex: they showed only small differences from the CF. However, FMT differed from CF in 7 of 14 sex-dimorphic indices of masculinity/femininity in body build. Of these 14 indices, 9 did not show a difference between FMT and CM. Hence, FMT presented a more masculine body build, particularly in fat distribution and bone proportions. Levels of T and A4 were significantly higher in FMT than in CF (T: 54.0 +/- 13.8 vs. 41.1 +/- 12.8; A4: 244.8 +/- 73.0 vs. 190.5 +/- 49.3), while DHEAS was higher in CM (3335 +/- 951) than in CF (2333 +/- 793) and in FMT (2679 +/- 1089). Altogether, 83.3% of FMT and 33.3% of CF were above normal values for at least one measured androgen. SHBG in FMT (1.21 +/- 0.70) and CF (1.87 +/- 0.91) was higher than in CM (0.49 +/- 0.18) and tended to be higher in CF than in FMT. Unbound T (T/SHBG ratio) was higher in FMT (72.0 +/- 67.6) than in CF (26.4 +/- 15.1) and correlated positively with manly body shape. Findings are discussed in relation to etiology of transsexualism.