Focusing on Hawaii, a state with 21.3% of the population being multi-racial according to the 2010 U.S. Census, this study aims to examine the existence and nature of health disparities between mono- and multi-ethnic Asian Americans and the importance of Relational Well-Being in affecting the health of Asian Americans. A series of ordinary least squares regression models that examine the direct and moderating effect of multi-ethnicity with indices of Relational Well-Being on physical health and mental health were estimated using Asian American data in the 2008 Hawaii Health Survey (N = 2,440). Multi-ethnic Asian Americans are found to enjoy better physical health and mental health compared to their mono-ethnic counterparts. Indices of Relational Well-Being such as Sense of Security, Sense of Resilience, and Sense of Family are stronger independent correlates of mental health compared to multi-ethnicity. Multi-ethnicity moderates the effect of some indices of Relational Well-Being such that Sense of Security benefits mental health and physical health more for the multi-ethnic group whereas Sense of Resilience benefits mental health more for the mono-ethnic group. Findings underscore the importance of multi-ethnicity and the construct of Relational Well-Being, which has its origins in both indigenous and Asian cultures, in understanding the health disparities among Asian Americans.