This study examines long-term effects of parental divorce on sibling relationships in adulthood and the role of predivorce parental conflict. It used large-scale retrospective data from the Netherlands that contain reports from both siblings of the sibling dyad. Results show limited effects of parental divorce on sibling contact and relationship quality in adulthood but strong effects on sibling conflict. The greater conflict among siblings from divorced families is explained by the greater parental conflict in these families. Parental conflict is a far more important predictor than parental divorce per se. Siblings from high-conflict families have less contact, lower relationship quality, and more conflict than do siblings from low-conflict families. Finally, when it comes to sibling relationship quality, the effect of parental divorce depends on the amount of parental conflict. Parental divorce has little effect on the quality of the relationship in low-conflict families, but it improves the relationship in high-conflict families. (Contains 2 tables.)