Using survey and semi-structured interview data collected in various religious congregations in urban and rural areas of Mozambique, this study analyzes how gender differences in perceptions of HIV/AIDS and preventive behavior are mediated by religious involvement. Logistic regression is employed to examine the effects of gender and of the interactions between gender and type of denomination--"mainline" (Catholic and Presbyterian) or "healing" (Assembly of God, Zionist, and Apostolic)--on female and male members' exposure to HIV/AIDS-related prevention messages, knowledge and perception of risks, and practice of prevention. The analysis detects women's disadvantage on several measures of knowledge and prevention but also suggests that gender differences are less pronounced among members of "mainline" churches. The semi-structured interview data further highlight how gender differences are shaped in different religious environments. Although the potential of faith-based institutions in combating the HIV/AIDS pandemic is undeniable, policy-makers need to heed important differences among these institutions when devising ways to harness this potential.