The present longitudinal study used data from 187 newlywed couples to examine the impact of the birth of the first child on self-esteem over the course of the first 5 years of marriage. Results suggest that the birth of the first child is associated with changes in parents’ (especially mothers’) self-esteem. For the average parent, these changes were negative with sudden declines in self-esteem in the year after childbirth and continuing gradual decreases throughout the remaining years of the study. A comparison group of couples who did not have children during the research period showed no changes in self-esteem, suggesting that the results seen in the parent sample may indeed be due to the birth of the first child. Discussion focuses on the implications of the results for theory and research on the development of the self-esteem.