The dynamic interplay of parental educational aspirations and children's academic self-concept was examined from late childhood through mid-adolescence within a transactional socialization framework. Parental and child data were gained from a representative Swiss sample within 3-year intervals (N[subscript T1] = 1118; 51% females; 28% migration background; M[subscript age] T1 = 9.26, M[subscript age] T2 = 12.14, M[subscript age] T3 = 15.32). Results from a random intercept cross-lagged panel model revealed positive associations between the two constructs at the between- and within-person level. Findings showed general and time-specific associations between children and parents and reciprocal spill-over effects, whereby higher than usual aspirations predicted higher than usual academic self-concept over time and vice versa, highlighting transactional processes in the context of educational transitions.