The question asked by this study was whether information on play behaviour of young children at-risk of learning difficulties could act as a diagnostic means of investigating emerging learning difficulties. A sociocultural perspective was taken to examine the role of interaction during the play of students in a regular primary school and in a special primary school using a multimethod approach. Groups of students from both schools were studied during eight 30-minute sessions over a period of 3 weeks. The groups were matched with respect to age and language development and then divided into two further groups of three students each per school. Each group was invited to build a zoo using toy animals and wooden blocks. The 32 sessions were videotaped, transcribed, and analysed microgenetically with measures involving the types of collaboration during play and metaplay. The results showed that the number of episodes and the most elaborate type of collaboration occurred more often in the regular primary school than in the special school, whereas the frequency of metaplay did not differ significantly between the schools. Fragments of discourse obtained during the sessions are presented and discussed. It is concluded from the findings that social play may emerge as a situated performance. Thus, information on social development of young children at-risk of learning difficulties needs to be related to the school as a context in order to improve diagnostic decision-making when placement of these children in special education is considered.