Research evidence indicates that children with autism may experience problems with functional play, in addition to their well-documented deficits in symbolic play. However, as a result of the tendency of previous studies to group all functional play into a single category, the precise nature and extent of this deficit remains unclear. The present study undertook a more refined analysis of such play, subtyping the functional acts into various categories, in terms of the developmental progression suggested by research with typical infants. The functional play of children with autism was compared to that of developmentally matched children with Down syndrome and typical infants. Although there were no group differences in overall measures of the proportion of total play time spent in functional play and in the number of functional acts performed, a closer analysis of the composition of this play did reveal striking, qualitative differences. The functional play of the autism group was less elaborated, less varied, and less integrated than that of the controls. The implications of these findings are explored in relation to current theoretical models of autism and in relation to the role of other people in mediating the appropriate use of objects.