This investigation used long-term longitudinal survey data from baby boomer women to identify whether strengthening gender role egalitarianism in early adulthood predicted declines in religious service attendance and religious intensity in later life. The aging of this cohort coincided with dramatic societal shifts in gender values and religiosity. The data were derived from 350 women participating in the Longitudinal Study of Generations, a study originally fielded in 1971 of families living in Southern California. Respondents were initially assessed in their late teens and early 20s and followed up to their early-to-mid 60s. Using growth curve modeling, we linked the change in egalitarian gender attitudes from 1971 to 1988 to a change in religiosity from 1994 to 2016. Women who became more egalitarian in their gender attitudes experienced sharper declines in religious intensity, but not in religious attendance in the period studied. Controlling for life-course transitions did not alter these results. The findings are discussed in terms of the connection between two asynchronous social changes occurring over the lives of women in a uniquely positioned birth cohort.