Purpose: The purpose of the present study was to examine the effectiveness of an instructional procedure called "aided language modeling" (ALM) on symbol comprehension and expression in 2 preschool children with autism who used few words functionally. ALM consists of engaging the child in interactive play activities and providing models of use of augmentative and alternative communication symbols during play. Method: A multiple-baseline design across sets of symbol vocabulary was used with 2 children who had autism. Four vocabulary items were taught in each of 3 legs of the design, for each child. Results: Both participants demonstrated increased symbol comprehension and elicited symbol production. In addition, both participants demonstrated that symbol comprehension and symbol production could be maintained. For both children, performance on symbol production lagged behind rate of responses on symbol comprehension. Conclusions: The current research presents preliminary evidence that a modeling intervention may be effective in increasing symbol comprehension and production, and may be an appropriate intervention strategy for some preschoolers with autism. Future research should continue to investigate this strategy and its effects on functional communication.