Reducing the prevalence of teenage pregnancy remains an elusive goal for public policy in Peru. We use longitudinal data from the Young Lives Study in Peru to investigate on an extensive set of early circumstances and life changes that might be the risk factors for teenage childbearing—about one out of five girls in the sample was a teenage mother. The use of longitudinal data allows us to reduce the methodological concerns common to this type of analysis. According to our results, growing up in a poor household, being raised in a single-parent household, leaving school at or before age 15, performing badly in school at age 12, and having the first sexual relation at or under age 16 are the key risk factors for early childbearing. From a time-varying perspective, we uncover the importance of changes in the characteristics of a child and household that occurred prior to childbearing. Among other factors, we find that improvements in self-efficacy and education aspirations during adolescence are associated with a decrease in the probability of early childbearing. Risk factors identified are considerably more relevant—in most cases, only relevant—for girls. From a policy perspective, our results suggest that initiatives aimed at improving school attendance, sexual education, and socioemotional competencies among adolescents might be effective tools to reduce the high rates of teenage pregnancy in Peru.