This study investigated the relationship between structural language skills, and communication skills, adaptive behavior, and emotional and behavior problems in pre-school children with autism. Participants were aged 3-5 years with autism (n = 27), and two comparison groups of children with developmental delay without autism (n = 12) and typically developing children (n = 20). The participants were administered standardised tests of structural language skills, and parents completed the Vineland Adaptive Behavior Scales and the Developmental Behaviour Checklist. Results indicated that for children with autism, communication skills, and in particular receptive communication skills, were associated with social and daily living skills, and behavior problems. Receptive structural language skills were associated with expressive communication skills. There were no associations found between structural language skills and social or daily living skills, nor behavior problems. The results of this study suggest that communication skills are more closely linked to functional and behavioral outcomes in autism than structural language skills. (Contains 3 tables.)