We determined the relationship between physical attractiveness and sexual maturity ratings (SMR-Tanner ratings) in a group of 30 boys and girls with delayed puberty. Using a hormone deplete/hormone replete model, subjects were treated with physiologic doses of depo-testosterone or conjugated estrogen at doses approximating early, mid-, and late puberty. We used a double-blind, placebo controlled, randomized, cross-over design during a 21 month period, alternating placebo with hormone every 3 months. Facial and clothed full body photos taken every 6 months were rated for attractiveness by 30 late adolescent girls using a 10 cm visual analogue scale. A rating of 0 was unattractive and 10 was attractive. The Fuller and Buttese time series, cross-sectional pooling technique was used to estimate the relationship between face attractiveness(FA) or body attractiveness(BA) and treatment or SMR. Beta coefficents (β) estimate the increase in FA or BA (dependent or outcome variables) as a result of treatment or SMR (independent variables) at each dose. Treatment resulted in increases in BA at the mid- (β=1.0) and high doses (β=1.1) (p<.02 for both) and in FA at low (β=1.1) mid(β=1.2) and high (β=1.2) doses (p<.01 for all doses). Increases in SMR for breast (B) in girls or genital (G) in boys, (β=.22) were associated with increases in BA (p<.0001) but not in FA. Increases in pubic hair (PH) SMR (β=.11) were associated with increases in FA (p<.02) but not BA for both boys and girls. The data suggest that treatment with sex steroids causes changes in both BA and FA. In girls, increases in B development (estrogen effect) are associated with increases in BA and increases in PH development (androgen effect) are associated with increases FA. In boys, increases in PH and G development(androgen effect) are associated with increases in both BA and FA. It is possible that these changes in both FA and BA are mediated through changes in SMR. Increases in attractiveness is an important beneficial effect of hormone replacement in adolescents with delayed puberty.