This study makes a unique contribution to the literature on single motherhood by assessing whether favorable attitudes toward single motherhood in adolescence are associated with subsequent childbearing behavior with the use of national data from Add Health. This study employs a longitudinal design, which allows it to link attitudes to behavior over time. Findings indicate important differences in single motherhood attitudes by race and ethnicity, family SES, family structure, religiosity, and future educational expectations. Controlling for theoretical mechanisms known to be associated with single motherhood, including culture (race and religiosity), opportunity costs (educational expectations and SES), and socialization and supervision (family structure), favorable attitudes toward teenage motherhood remain significantly related to the probability of becoming a single mother in early adulthood. Attitudes, therefore, have an impact beyond the theoretical and commonly measured influences upon single motherhood. This independent effect of attitudes is discussed in the paper.