We studied parents' direct involvement in adolescent sibling relationships, including parents' reactions to sibling conflict and their time spent in the company of the sibling dyad. Participants were 185 White, working- and middle-class families; firstborns averaged 15 and secondborns averaged 13.5 years of age. In separate home interviews mothers, fathers and both adolescents described their personal and family relationship qualities and experiences. In a series of 7 evening phone calls, family members reported on each day's activities including the time they spent and their companions in 63 daily activities (e.g., do dishes, play sports, talk on phone). Analyses revealed 3 general conflict reactions by parents: (a) noninvolvement (e.g., tell siblings to work out problem themselves); (b) intervene (e.g., step in and solve problem); and (c) coach (e.g., give advice about how to solve problem). We found mother-father differences in conflict reactions and time spent with siblings; differences in parents' direct involvement as a function of the gender constellation of the sibling dyad also were evident. Direct involvement was linked to sibling relationship qualities and explained variance beyond that accounted for by an index of indirect involvement, that is, parental warmth. Further, parents' orientations toward autonomy were linked to the indices of involvement such that parents with stronger autonomy orientations were less involved, and parents' orientations explained variance in their involvement beyond that explained by adolescent characteristics.