The paper analyzes the significance of parents' play routines as an aspect of home intervention programing of play behaviors with developmentally delayed young children. Three sources of child development research are noted: the studies demonstrating a rationale for parent-child play, emphasis on the early aspect of intervention, and the use of play as a natural medium for parent-child interaction. A study is reported in which 16 low income families received weekly play training procedures and activities and 16 families were controls. The 6 month program featured a five part instructional cycle, led and modeled by a home visitor. (Examples are given of objectives and play routines.) Pre- and posttest scores were computed on the Parent-Child Perspective Taking: Child Scale; the PAAT Inventory: Child Form; the Parent-Child-Play Preference Inventory; and the Parent-Child-Perspective Taking: Parent Scale. The major result was that parents trained in using play routines significantly affected their children's imaginative play behaviors. Children in the play training group showed significantly greater quantities of imaginative play activities in home and school situations. (CL)