Objectives: Children with ADHD obtain lower scores than their peers on standardized language measures but less is known about their conversational language skills. We tested the ability of children with and without ADHD to monitor and repair their language during a conversation (social discourse) with a young adult. Methods: Forty-nine 9- to 14-year-old children previously diagnosed with ADHD (17 in partial remission) and an age and sex-matched sample of typically developing (TD) children engaged in a conversation with a young adult. Their conversations were recorded, transcribed, and coded for structural and pragmatic language use. Language error and correction rates were compared across the two groups, for the whole sample and for those meeting full criteria for ADHD. Results: The ADHD group made significantly more structural language errors, specifically morphosyntactic mistakes and word repetitions. In their pragmatic language use, children with ADHD were more likely to make unrelated utterances and were less successful in repairing dysfluent responses. The adult conversational partners made more attempts to keep TD participants engaged in conversation and rated them as more likable. Conclusions: Subtle differences were identified in the structural and pragmatic language use of children with and without ADHD during social discourse. Conversation partners were more engaged in their interactions with TD children and appeared to experience these interactions more positively. The language skills of children with ADHD, including their conversation skills, should be monitored and considered as targets for intervention.