The present study explores the bidirectional associations between parental behavior and child externalizing behavior in the context of two intervening variables: child's personality as a moderator of the effect of parental behavior on later child behavior; and parental self-efficacy as a mediator of the effect of child behavior on later parental behavior. Data were collected twice within one year from a sample of 340 preschoolers and their parents. Using latent variable SEM, three models were computed separately for mother-child and father-child dyads. A bidirectional effect was verified for the mothers, but only a child effect was observed for the fathers. Expected mediation by self-efficacy was verified. Finally, a partial moderating role for child's personality was demonstrated. (Contains 2 notes, 3 tables, and 4 figures.)