Children who lack functional spoken language are candidates for augmentative and alternative communication (AAC). Aided AAC and naturalistic interventions offer the potential to extend the communication functions demonstrated by children with autism spectrum disorder (ASD) who are nonspeaking. Related intervention research, however, has been limited, in that interventions have generally targeted a limited range of communication functions taught in highly structured, decontextualized environments. The aim of this study was to investigate the efficacy of an intervention that combined aided AAC with a naturalistic intervention -- enhanced milieu teaching (AEMT) - to increase symbolic communication in children with autism spectrum disorder. Three children with autism spectrum disorder participated in a multiple probe design, in which a range of communication functions were targeted using the AEMT. Results showed increases in the use of symbolic communication from baseline to intervention phases, which were found to be statistically significant for two of the three children (phi 0.7-0.81; p < 0.001). Intervention outcomes were generalized to a communication partner not involved in the intervention and maintained over time for all children. The study provides preliminary evidence that communication functions beyond object requests could be taught using a systematic, multi-element approach implemented across activities.