Parental self-efficacy (PSE) describes parents' beliefs about being able to handle developmentally specific issues and being able to influence their child in a way that fosters the child's positive development and adjustment (Bandura, 1997). Parents of adolescents have been shown to feel less efficacious than parents of preadolescent children (Ballenski & Cook, 1982), but little is known about the factors behind low levels of PSE among parents of adolescents. This study examined mean-level changes in PSE and predictors of change among parents of adolescents. The sample was derived from a 3-wave longitudinal data set of 398 parents of children starting spanning early (11 or 12 years) to middle (14 or 15 years) adolescence (47% boys). Latent growth curve analysis was performed, and it was hypothesized that theoretically driven predictors reflecting the developing child, as well as the ecological context, would predict the level of PSE. Despite generally high levels of PSE across all time points, parents decreased in PSE during the developmental period. Some predictors were of particular importance for the level and amount of change in PSE, such as physical changes in the child, parents' target-based expectations for risk taking during adolescence, the quality of parent--adolescent communication, and ethnicity. This study adds insight into the development of PSE during the critical transitional period of early and middle adolescence. The findings advance theory of PSE, as it illuminates why some parents' decrease in PSE more than do other parents.