Parents in an increasingly diverse U.S. must contend with how confident or efficacious they feel in transmitting culturally-relevant messages to their children. The current study centers on this understudied concept of cultural parenting self-efficacy (PSE) and examines how efficacy related to three separate tasks of heritage, American, and bicultural socialization is associated with child grade, parental involvement with their children, and key demographic variables (e.g., child gender, parent gender, family socioeconomic status). Parents (65% fathers; 78% U.S.-born) of at least one child in grade 6–12 provided survey data through an online study. Parents were from Latinx (n = 158) and Asian American (n = 61) backgrounds. Using Mplus, path analyses suggest that, among Latinx parents, lower bicultural socialization efficacy is associated with greater child grade. Among both Latinx and Asian parents, higher parental involvement is associated with higher cultural PSE (related to heritage, American, and bicultural socialization tasks). Further, for both American and bicultural PSE, Latinx parental involvement interacted with the negative effect of child grade suggesting that parent-child involvement could counteract possible challenges to efficacy. The results point to cultural PSE as an additional layer of complexity to understand in light of cultural socialization among families from minoritized backgrounds. Further implications are discussed in light of parenting and family adjustment.