Parenting self-efficacy (PSE) has been linked to a variety of important child and family outcomes, including child internalizing and externalizing problems. However, there is uncertainty regarding the relation between PSE and these problems as a function of child age. The current study examined: (1) the associations of PSE and child age with internalizing and externalizing problems and (2) the role of age as a potential moderator in the relation between PSE and internalizing and externalizing problems. Participants included youth ranging from 5–18 years of age in the southeastern United States (N = 276, M age = 11.27, 55.6% male). Hierarchical regression analyses indicated child age and PSE were negatively associated with externalizing problems, and the relation between PSE and externalizing problems was constant as a function of age. Among late adolescents, PSE was not associated with internalizing problems. However, among youth in middle childhood and early adolescence, PSE was negatively associated with internalizing problems. Implications of study findings for future research and practice are discussed.