The purpose of this study was to determine the effects of a cooperative learning (CL) intervention on the levels of social and task engagement of a child with autistic spectrum disorder (ASD) conducted in a mainstream class setting and a child with ASD implemented in a special needs class setting. The target children were two 8-year-old boys diagnosed with high functioning autism. Both children were placed in CL groups which included three typically developing peers, one male and two females. Four baseline sessions taught in a traditional teaching format and seven CL intervention sessions based on a "learning together/conceptual approach" took place. All sessions were recorded for video analysis. CL was found to be successful in substantially increasing the level of social engagement for both the child in the special needs class and the child in the mainstream class. CL was not found to facilitate task engagement. Active task engagement was found to remain relatively stable and passive task engagement was found to decrease for one child and remain stable for the other. Teacher concerns and issues relating to the practical implementation of CL in both settings are discussed. (Contains 1 table, 2 figures and 2 notes.)