BACKGROUND: Although health inequality between young adult women and men has been strikingly evident in symptoms of ill health, we found no studies examining these inequalities with a focus on positive health and performance. OBJECTIVE: The aim of the present study was to examine possible inequalities between young adult women and men in a combined assessment of positive health and health-related performance. METHODS: Women and men aged 18 to 25 years studying medicine or computer science at 6 colleges/universities in 5 cities in Sweden were recruited for this study. All respondents answered a Web-based questionnaire regarding health, health-related performance, information and communication technology exposure, mood, and individual factors. A combined assessment of excellent health and health-related performance (EHHP) was defined and tested. Prevalence ratios (PRs) with 95% CIs of EHHP were calculated separately for female and male respondents. To assess potential determinants of EHHP, differences in the relationships between EHHP and the explanatory factors were compared for both sexes. Results: In a study group of young adult students consisting of 1046 women and 1312 men, women were less likely than men to have EHHP (PR 0.90 [95% CI, 0.83-0.98]). This inequality was even stronger within each course of study (medicine or computer science). Health-related factors showed similar patterns of relationship to EHHP for women and men; however, the strength of these relationships differed between the sexes. Logical relationships were observed between EHHP and almost all of the symptoms as well as between EHHP, the mood index, and health-related behavior. CONCLUSIONS: The well-known inequality in symptoms of ill health between young adult women and men was prevalent even in a combined assessment of positive health and health-related performance. That this inequality was prevalent in a relatively homogeneous sample of young adults indicates the importance of gender-based psychological and psychosocial factors beyond the more well-known structural gender-differentiating factors of vertical and horizontal segregation and disproportional responsibilities for domestic work. It may therefore be essential to emphasize these gender-based psychological and psychosocial factors when designing future studies and health promotion programs.