Data were taken from the National Longitudinal Survey of Work Experience of Youth, which each year for the last 8 years has obtained prospective and retrospective information from a representative sample of U.S. adolescents and young adults. Multivariate analysis shows that women who first give birth at ages 16 and younger are more likely to bear a second child within the next 2 years (26 percent) than are women who have their first child at ages 17-18 (20 percent) or at ages 19-22 (22 percent). Among whites, age at first birth has little effect on the proportions who have a second birth quickly, but among blacks, it has a significant inverse effect, with younger women more likely than older women to have a second child quickly. At nearly all ages at first birth, Hispanic mothers are more likely than either whites or blacks to have a second birth soon after the first. Socioeconomic background, marital status at first birth, and desire for the first birth also effect the pace of repeated childbearing. Teenage mothers who are married at their first birth are more likely than their unmarried counterparts to bear another child quickly. This suggests that educational programs may need to focus more on altering attitudes toward early marriage and childbearing than on just altering attitudes toward early childbearing. 7 tables, 6 references.