Many children with Down syndrome demonstrate deficits in phonological awareness, a prerequisite to learning to read in an alphabetic language. The purpose of this study was to determine whether adapting a commercially available phonological awareness program to better align with characteristics associated with the behavioral phenotype of Down syndrome would increase children's learning of phonological awareness, letter sounds, and words. Five children with Down syndrome, ages 6 to 8 years, participated in a multiple baseline across participants single case design experiment in which response to an adapted phonological awareness intervention was compared with response to the nonadapted program. Results indicate a functional relation between the adapted program and phonological awareness. Suggestions for future research and implications for practice are provided.