OBJECTIVE To examine the communicative profiles of children with autism spectrum disorders (ASD) in the second year of life. METHODS Communicative acts were examined in 125 children 18 to 24 months of age: 50 later diagnosed with ASD; 25 with developmental delays (DD); and 50 with typical development (TD). Precise measures of rate, functions, and means of communication were obtained through systematic observation of videotaped behavior samples from the Communication and Symbolic Behavior Scales Developmental Profile (A. Wetherby & B. Prizant, 2002). RESULTS Children with ASD communicated at a significantly lower rate than children with DD and TD. The ASD group used a significantly lower proportion of acts for joint attention and a significantly lower proportion of deictic gestures with a reliance on more primitive gestures compared with the DD and TD groups. Children with ASD who did communicate for joint attention were as likely as other children to coordinate vocalizations, eye gaze, and gestures. Rate of communicative acts and joint attention were the strongest predictors of verbal outcome at age 3. CONCLUSIONS By 18 to 24 months of age, children later diagnosed with ASD showed a unique profile of communication, with core deficits in communication rate, joint attention, and communicative gestures.