This paper examines the presence of spontaneous imitation within the social interactions of young people with developmental delay and their adult carers. There have been only a handful of observational studies examining imitation in this population, despite the relevance of such work to contemporary theoretical debates about imitation and the potential that imitation holds as an intervention for promoting communicative skills. The play of eight young people and 13 adult carers over 10 sessions at an after-school club was videotaped and analysed for the presence and impact of spontaneous imitative bouts. Results showed that, in the majority of cases, it was adults who initiated imitative bouts and that the young people generally did not reciprocate such acts. However, even such brief instances of adult imitation were sufficient to increase the children's subsequent smiles and speech vocalizations, as well as the adults' own use of smiling, eye contact, and speech vocalizations. These findings confirm that these young people are sensitive to imitation. The implications for designing interventions that promote communicative exchanges in young people with developmental delay are discussed. (Contains 3 tables.)