The purpose of this study was to test a model of adult-child play interactions in preschool classrooms, based on the work of Vygotsky and neo-Vygotskian scholars. The model predicts that adults will tailor the play support they provide to the immediate needs of individual children, and that this will lead to subsequent independent play. Classroom interactions between eight preschool teachers and 32 students were videotaped, transcribed, and analyzed over a six-month period. Interviews were conducted with the eight adult participants to confirm and elucidate findings from observed classroom behaviors. Distinct types of play support needed by children and given by teachers were identified. These were operationally defined; definitions were used to create a coding system that was found to have high inter-rater reliability. Sequential analyses were conducted to determine goodness-of-fit between teacher responses and children's needs. Behavioral outcomes of a good fit were also examined. Findings support the model tested here. Teachers often responded to children's play with behaviors matching the level of support needed. Good-fit interactions more frequently led to autonomous subsequent play than poor-fit interactions. (Contains 5 tables and 2 figures.)