How individual-level social capital relates to adult health and well-being was examined using data from a cross-sectional interview survey in East Asia (Japan, South Korea, Singapore, five areas in Mainland China, and Taiwan) in 2002-2004. The number of self-reported somatic symptoms, subjective health satisfaction, life satisfaction and social capital indicators, as well as socio-economic status (SES), were analyzed by a logistic regression model. Adjusting for SES, social capital measured by belonging to organizations and weakness in "norms of reciprocity" were related to a greater number of self-reported somatic symptoms (p<0.001 for both). Lack of trust in organizations (p<0.001) and of a person to consult (p=0.012) were related to poor health satisfaction. Lower "interpersonal trust" (p=0.016), weakness in "norms of reciprocity" (p<0.001) and lack of trust in organizations (p<0.001) were related to poor life satisfaction. Gender inequality was observed across countries, but the relationships varied according to the health indicator. Specifically, self-reported somatic symptoms were more numerous and health satisfaction was worse in women (p<0.001), but life satisfaction was worse in men (p=0.017). The analyses provide evidence that dimensions of social capital are positively associated with self-reported somatic symptoms and overall well-being in East Asian countries.