Thirty-five children who received an autism spectrum diagnosis at the age of 2 years (24 with autism, 11 with PDD-NOS) were re-evaluated 2 years later to examine factors related to the development of spoken language. Child variables (play level, motor imitation ability and joint attention) and environmental variables (socioeconomic status and hours of speech/language therapy between ages 2 and 3) were used to predict an aggregate measure of language outcome at age 4. After controlling for age 2 language skills, the only significant predictors were motor imitation and number of hours of speech/language therapy. Implications of these results for understanding the early developmental course of autism spectrum disorders and the effects of intervention are discussed.