Parenting self-efficacy (PSE) is an important mechanism linking maternal adjustment to children's healthy development. The present study investigates (1) how PSE among first-time mothers changes over children's first two years of life, (2) how these patterns of change are associated with early maternal risk factors, and (3) how trajectories of PSE are related to children's cognitive development at age 2 among a racially diverse sample of 684 first-time mothers ranging in age from 15 to 35 years. Results of confirmatory factor analyses revealed that the six-item measure used to assess PSE did not load onto a common factor; therefore, growth models were fitted at the individual item level. In terms of change over time, analyses of item thresholds revealed that changes in PSE were nonlinear, with most items showing an initial increase followed by a decline as children entered toddlerhood. Analyses of maternal risk factors revealed that early childbearing (i.e., teenager at first birth) had a negative effect on prenatal efficacy in the abilities to be a good role model, provide material needs, and effectively parent. In other words, during the third trimester of pregnancy, teenagers demonstrated doubt in their parenting skills in three out of the six domains of PSE. Furthermore, maternal histories of abuse (i.e., verbal and physical abuse during childhood) had a negative effect on prenatal efficacy in providing material needs. In turn, prenatal perceived ability to provide material needs was the only domain of PSE that significantly predicted higher children's cognitive development at age 2. Results are discussed in terms of maternal risk for low PSE, recommendations for PSE measurement, and the implementation of intervention programming designed to facilitate the development of PSE among at-risk mothers.