To investigate the development of preschoolers' social-cognitive play behaviors 10 preschoolers each at three ages, 2, 3, and 4 yr., were observed in their classrooms on 15 occasions by a time-sampling schedule. Children's social-cognitive behaviors were coded according to Parten and Smilansky's systems. Analyses indicated that children's play became more social as they grew older. 3- and 4-yr.-olds, however, engaged in more non-social dramatic play than did 2-yr.-olds. 3- and 4-yr.-old girls engaged in more non-social functional play than did boys. Boys, however, engaged in more non-social dramatic play than girls. Increased sampling is needed.