The sibling relationship of adolescents with and without intellectual disabilities was examined. Participants were 70 sibling dyads--each dyad was comprised of one 12-year old adolescent with (N = 23) or without intellectual disabilities (N = 47). Sibling relationships, behavior problems, and social skills were assessed using mother reports. Results revealed three findings. First, for typically developing adolescents, mothers reported more warmth in the sibling relationship for opposite sex dyads. For adolescents with intellectual disabilities, mothers reported more warmth in the sibling relationship for same-sex dyads. Second, for typically developing adolescents, mothers reported more status/power differences when the sibling was younger than when the sibling was older. For adolescents with intellectual disabilities, birth order did not affect status/power in the sibling relationship. Third, for typically developing adolescents, conflict was related to internalizing behavior problems. For adolescents with intellectual disabilities, conflict was related to externalizing behavior problems. Implications, limitations, and future directions are discussed. (Contains 2 figures and 3 tables.)