This study tests competing explanations for the link between the transition to motherhood and declines in wives' marital satisfaction. Using data from the first and second waves of the National Survey of Families and Households (N = 569), we found that new mothers' marital satisfaction declines could be attributed to reductions in wives' quality time spent with their husbands and to increases in perceptions of unfairness in housework. Family role traditionalization in the wake of the birth of a child did not directly explain marital satisfaction declines but was linked to perceptions of marital unfairness. Attendance at religious worship services did not moderate the association between the transition to motherhood and marital satisfaction changes. (Contains 3 tables and 1 note.)