Abstract: Young children learn by actively interacting with their environment. They explore their surroundings to play with objects and with other people. Through these interactions, they gain new knowledge and understanding which contributes to their social and cognitive development. Young children with autism may have difficulties interacting with their environment because of their specific deficits in symbolic play and joint attention. The purpose this study was to provide information on play and joint attention behaviors in a naturalistic environment, the preschool special education classroom, for children with autism (N=27) as compared to children with mental retardation or other developmental delays (N=28). The participants were observed in their classroom environment for approximately two hours over three separate days. The children were also assessed individually on visual, motor, receptive, and expressive language skills as well on play and joint attention. The children ranged in age from three to five years old and their mental ages ranged from 18.5 to 59 months. Child characteristics and demographics were not significantly different between the two groups. Results show that children with autism spent more of their time in an unengaged state than in any other engagement state, which directly translated into fewer symbolic play and joint attention behaviors. Additionally, children were not showing their optimal levels of symbolic play at school, nor were their teachers targeting those levels. Compared to children with mental retardation or other developmental delays, children with autism displayed fewer responses to and initiations of joint attention. Finally, the findings indicate that although teachers seldom focused on symbolic play and joint attention in their teaching, when they did, it was rarely for the purposes of increasing symbolic play and joint attention skills. These findings suggest the importance of teachers targeting play and joint attention skills in their preschool special education classes, specifically for children with autism.