Masculinity (M) and Femininity (F) were related to multiple dimensions of self-concept for responses from 962 high school students. Androgyny theory predicts that F, as well as M, will contribute positively and uniquely to self-concept, but previous research has typically found that the contribution of F is nil or even negative after controlling for the contribution of M. However, in the present research, M scores and F scores each contributed positively and uniquely to the prediction of self-concept. In a few areas of self-concept the contribution of F was actually more positive than the contribution of M, and these tended to be the areas in which females had higher self-concepts than males. Surprisingly, the contribution of M to the prediction of self-concept was somewhat greater for females than for males, while the contribution of F was as large or larger for males as for females. Nevertheless, the relative contribution of M and F to the prediction of self-concept had more to do with the area of self-concept than with the gender of the respondent. The issues of social desirability, the possible bipolarity of MF, and the multidimensionality of both MF and self-concept are discussed. (Author)