Traditional assumptions that sex-role conformity is positively related to psychological adjustment in young children have not, to date, been examined empirically. Seventy-four preschool children, 37 boys and 37 girls aged 3 to 5, were observed over a 3-month period to determine their frequency of play in male and female sex-typed activities during the freeplay period in their classrooms. Teacher ratings on the Kohn and Rosman Symptom Checklist and Social Competence Scale were correlated with individuals' rates of play in male and female preferred activities (M and F scales, respectively). Results indicated that boys' play with male-preferred toys was related to high scores on the "aggression/defiance" dimension of the Symptom Checklist, while boys who scored highly on play in female-preferred activities received high scores on the Social Competence dimension labeled "conforming to classroom rules." For girls, play with male-preferred toys was negatively related to the "apathy/withdrawal" dimension of the Symptom Checklist. These results do not confirm the hypothesis that sex-typed behavior is positively related to adjustment, and they suggest that for both sexes, play in opposite sex-typed activities may contribute positively to children's social and academic functioning in the classroom.