This research examined the overtime reciprocal relations between maternal and paternal harsh discipline and children's externalizing behavior. Seven hundred two father–mother dyads of children (6–9 years of age at baseline) completed measures of parental harsh discipline and children's externalizing behavior at five time points, 1 year apart. Autoregressive latent trajectory models revealed that maternal and paternal corporal punishment predicted subsequent children's externalizing behavior (parent‐driven effects), whereas children's externalizing behavior predicted subsequent maternal and paternal psychological aggression (child‐driven effects). The parent‐driven effects became stronger, whereas the child‐driven effects were equally strong across time. Furthermore, the parent‐driven effects for corporal punishment were found for both boys and girls, whereas the child‐driven effects for psychological aggression were found only for boys.