Background: The nature and characteristics of the peer social networks of young children with Down syndrome (DS) in classroom settings were examined within a developmental framework. Method: Comparisons were made with younger typically developing children matched on mental age and typically developing children matched on chronological age. Results: Similar patterns were found for all three groups for most peer social network measures. However, group differences were obtained for measures of teacher assistance and peer interactions in unstructured situations. Conclusions: Positive patterns appeared to be related to the social orientation of children with DS and the special efforts of teachers to support children's peer social networks. Findings also suggested that fundamental peer competence problems for children with DS remain and may best be addressed within the framework of contemporary models of peer-related social competence.