Using quantitative and qualitative data from three culturally heterogeneous ethnic groups in Malawi, I show that differences in postpartum sexual abstinence are closely associated with community-specific rationales for the practice, particularly differences in the definition and timing of child-strengthening rituals that couples are required to perform before resuming intercourse. Contrary to conventional wisdom, the primary rationale for abstinence in the study areas is not linked to child spacing. Among Tumbukas in the north, most women perform the ritual immediately after resuming menstruation. Among the other ethnic groups, the rituals can be performed at any time after the end of postpartum bleeding. The study underscores the utility of the complementary micro-level approach in understanding reproductive behavior in sub-Saharan Africa.