Despite research demonstrating the importance of recess and free play for children, schools have been reducing free play time for more academic pursuits (Ramstetter et al. in "J Sch Health" 80:517-526, 2010; Waite-Stupiansky and Findlay in "Educ Forum" 66:16-25, 2001). Recently, there has been renewed interest in understanding the critical role that free play has for children's development. The current study was designed to contribute to this literature as well as investigate how the type of environment in which children play influences their behaviour in the classroom. Children in grades 3-5 were tested before and after recess on cognitive measures of sustained attention and creativity. We found an increase in children's sustained attention after recess. We additionally found that the type of environment in which children played differed depending on children's behaviour and traits. Our findings suggest that recess is an important factor in children's performance in school and should be considered an important part of the school day. Furthermore, we suggest that researchers should consider how individual differences influence the relationship between recess and children's performance in the classroom. Implications of this research for schools are considered.