Children with social communication disorders are known to experience more problematic peer relations than typically-developing children. However, detailed observation of their behaviour and communication during interaction with peers has not previously been undertaken. Micro-analytic observational methods were used to analyse the audio-taped interaction of children (N = 112) selected from mainstream schools (ages 5-6 years-old) on a computerised dyadic collaborative task. Comparisons were made between children with average-to-high- and low-pragmatic language skill as measured by the Test of Pragmatic Skills. Dyads were composed of an average-to-high-skilled child plus a low-skilled child (32 dyads), or of two average-to-high-skilled children (24 dyads). Consistently with their pragmatic language scores, low-skilled children were more likely to ignore other children's questions and requests than were average-to-high-skilled children. When average-to-high-skilled children worked with low-skilled children, as opposed to with other average-to-high-skilled children, they showed some sensitivity and adaptation to these children's difficulties; they used significantly more directives, clarification and provided more information. However, there was a cost in terms of the emotional tone of these interactions; when working with low-skilled children, the average-to-high-skilled children expressed considerably more negative feelings towards their partners than with another average-to-high-skilled child. In conclusion, observation of the interaction of average-to-high- and low-skilled children suggests promise for peer-assisted interventions and specifies which communicative behaviours could be targeted. However, care should be taken to manage the affective climate of these interactions for the benefit of all children involved.