The present study used a daily reporting design to examine the bidirectional spillover in conflict and conflict strategies between the interparental relationship and the parent–child relationship. Participants were 60 parents with a preadolescent child at risk for aggressive behavior. Parents reported on their experience of interparental and parent–child conflict and their use of constructive and destructive conflict strategies through daily telephone interviews over 7 days. Each day was divided into 3 equal time periods roughly corresponding to early morning, daytime, and evening. Time-lagged analyses investigated the spillover in conflict within and across days. Results revealed that the presence of interparental conflict significantly predicted the presence of parent–child conflict 1 time period later and 1 full day later. Likewise, the presence of parent–child conflict significantly predicted the presence of interparental conflict 1 full day later. In terms of conflict strategy use, results revealed that parents who engaged in constructive patterns of interparental conflict were more likely to engage in constructive patterns of parent–child conflict 1 time period later and 1 full day later. Reciprocal effects for constructive parent–child conflict predicting subsequent interparental conflict were significant across all 3 time lags assessed. There were no significant, bidirectional effects for the spillover in destructive conflict. Findings have important clinical implications.