The profiles and developmental trajectories of adaptive behavior were cross-sectionally examined in 80 children with Down syndrome ages 1 to 11.5 years using the Vineland Adaptive Behavior Scales. Profile findings indicated a significant weakness in communication relative to daily living and socialization skills. Within communication itself, expressive language was significantly weaker than receptive skills, especially when children's overall communicative levels were above 24 months. One to 6-year-old children showed significant age-related gains in adaptive functioning, but older subjects showed no relation between age and adaptive behavior. There was, however, increased variability within this older group, implying that not all children plateau in adaptive development during the middle childhood years. Implications for development in Down syndrome and intervention programs were discussed.