Increasingly, children with Down syndrome are receiving their education in mainstream schools but little research has investigated whether these placements may influence language and memory development. The present study compared 22 children with Down syndrome in mainstream school placements matched for chronological age with 22 children attending special schools in a different LEA where mainstream placements were rare. The children were assessed to obtain measures of the following language and memory abilities: receptive vocabulary; grammar comprehension; sentence repetition; digit span; face recognition; and memory for hand movements. Children in mainstream placements achieved significantly higher scores for vocabulary, grammar and digit span measures, but not for non-language based memory measures. More importantly, even after controlling for age and receptive vocabulary, grammar understanding and digit spans were significantly greater for the mainstream children.