We examined racial/ethnic differences in five measures of religious involvement (worship attendance, religious social support, importance of faith, comfort from religion, and frequency of prayer or meditation) among 2,690 women, age 42-52 years, participating in the Study of Women's Health Across the Nation (SWAN). The women reported five racial/ ethnic identifications: white, African American, Hispanic, Japanese, and Chinese. A large proportion of the Asian and Hispanic women were born outside the United States (Japanese 48 percent, Chinese 69.5 percent, Hispanic 89.1 percent). African-American and Hispanic women reported the highest levels of religious involvement. White and Japanese women reported similar levels of involvement for four measures. Compared to the white women, the Chinese women reported similar levels of worship attendance and religious social support, but lower levels for the other three measures. These racial/ethnic differences were not explained by differences in religious preference, acculturation, or sociodemographic factors. With the exception of worship attendance, in adjusted models, measures of acculturation were not significantly associated with religious involvement.