The goal of this paper was to further our understanding of adolescents' adjustment by studying multiple components of siblings' unique family environments using the difference score methodology. Self-report data about marital conflict, parent-child hostility and adolescents' adjustment were obtained from 114 sibling pairs (mean ages = 14 and 16 years) and their parents. Results indicated that adolescents who had higher appraisals of self-blame for marital conflict than their siblings also had more hostile parent-child relationships than their siblings. In addition, siblings' differential experiences of their family environments were associated with differences in siblings' externalizing, but not internalizing, problems. When considered together, differences in parent-child hostility, appraisals of self-blame and exposure to marital conflict predicted independent variance in differences in siblings' externalizing problems. Results are discussed in the context of using difference scores as a method to study siblings' unique experiences.