The use of complex syntax was investigated in narrative language samples of older children and adolescents with Down syndrome (n = 24) and a group of typically developing children matched on mean length of utterance. Both groups used conjoined and subordinate sentence forms and did not differ significantly in either the proportion of utterances containing complex sentences or in the variety of complex sentence types used. The analysis of developmental patterns suggested a similar order of acquisition across groups. The findings indicate that syntactic development in individuals with Down syndrome continues into late adolescence and is not limited to simple syntax. This study does not support earlier findings of a critical period effect in syntactic development in Down syndrome based on age or syntactic complexity.