We investigate the factors that influence adolescent self-assessed health, based upon surveys conducted between 2000 and 2004 of high-school seniors in Washington State (N = 6853). A large proportion of the sample (30%) was first and second generation immigrants from Asia, Latin America, and Eastern Europe. Findings include a robust negative effect of female gender on self-reported health that is largely unmodified by demographic, developmental, social capital, and parental support variables, gender differences in the covariates of self-reported health, and the tendency of male adolescents of Cambodian and Vietnamese origin to report lower levels of self-reported health despite controls for other health-related individual characteristics. Social capital dimensions such as positive school affiliation, social network cohesion, and a safe learning environment were found to covary with the self-reported health of adolescent females. (Contains 1 figure and 6 tables.)