This study examined relationships between prelinguistic variables from the MacArthur-Bates CDI and the development of language comprehension and production in children with autism. Forty-four children were assessed at baseline and 6, 12, 24, 33 and 53 months later. Growth Curve Modeling was used to examine the extent to which three composite CDI variables and three CDI item groupings predicted language development over 4–5 years. When examined individually, prespeech and early gestures were significant predictors of change for both comprehension and production, but late gestures were not. In addition, initiating joint attention and games and routines predicted comprehension and production over 4–5 years, and conventional gestures also predicted production. When all factors were considered simultaneously, children's ability to participate in games and routines was the only significant predictor of language production over time. The results are discussed with regard to their implications for understanding the complex factors that affect developmental outcomes.