The purpose of this study was to explore gender differences in the self- esteem, sex- role identity, achieving styles and career aspirations of 164 male and female college student leaders. Also explored were potential differences between student leaders of single-sex and mixed-sex groups across the same dimensions. All presidents of registered student organizations were asked to participate in the study. Seventy-one percent of the presidents responded and were included in the study. Respondents were administered the Rosenberg Self- esteem Scale, the Bern Sex- role Inventory, the L-BLA Achieving Styles Inventory and a questionnaire containing items on career aspirations. No significant differences were found between male and female student leaders on the self- esteem or sex- role identity variables. Significant gender differences were found on five of the nine achieving styles and on two of the indicators of career aspiration -- college major and preference for a full-time or interrupted career. No significant differences were found between student leaders of single-sex and mixed-sex groups.