This study examined the correspondence between children’s indoor and outdoor play in a preschool environment to investigate whether the children maintained a tendency to engage in a particular type of play irrespective of the environment, or whether they changed the type of play according to the environment. Play behaviours of 18 three-year-old and 20 five-year-old children were observed in both settings in an urban preschool in Japan. Various characteristics of play were examined based on cognitive play categories, social play categories, and types of objects used. The results indicate that children do not maintain fixed play behaviour without taking into consideration the play settings: their play differed greatly in accordance with the play setting. Not every child showed the same differences in play corresponding to differences in the setting. However, for each age group there was a qualitative difference based on the setting. For the three-year-olds, the “subject of interest” changed between settings, whereas for the five-year-olds, the “participation in society” changed related to the setting (indoor or outdoor). The “relation with the environment” was greater for both age groups in the outdoor setting. There were no significant sex differences. (Contains 3 tables and 2 figures.)