This study investigates interaction in dialogues between children with language impairment (LI) and peers of different ages and at two different times, taking into account the language skills of the children with LI. The hypotheses tested were that dialogues between more mature children are more coherent and that the degree of language problems of the child with LI is not directly associated with characteristics of the dialogues. Nine children with LI (aged 3;9–5;0 at time I) were recorded with an age-similar and a language-similar peer on two occasions with a one-year interval. The analysis focused on responsiveness and assertiveness in the dialogues as wholes. Dialogues between older children were more coherent and mutual influence within the dialogues was significant at both times. The children with LI tended to be more assertive with the younger peer. The language skills of the children with LI only partly explained the characteristics of the dialogues. Intervention for children with LI should focus on enhancing their opportunities to interact with peers of different ages.