Background: Traumatic brain injury (TBI) is a leading cause of hospitalisation and disability worldwide. There is general consensus in the literature reporting poor communication and social outcomes for individuals with TBI. While the literature is extensive in describing cognitive communication difficulties manifesting in the discourse of individuals with TBI, it does not include genres that represent everyday interactions. Furthermore, there are very few studies in the literature that explore interactions of individuals with TBI and their friends, even though it is common for individuals with TBI to lose friends within the first year of their injury. Aims: To explore discourse participation and performance of individuals with and without TBI in a shared problem-solving task with their friends. Methods & Procedures: Ten participants with severe TBI were matched with ten control participants for sex, age, and education. Participants problem-solved names and functions of unfamiliar objects with their friends. The resulting discourse was transcribed, divided into moves, and analysed for its generic structure potential (GSP) within a systemic functional linguistics approach. The number of moves contributed by each participant (participation) and frequencies of moves assigned to generic structural elements (performance) were tallied and then statistically analysed. Results & Outcomes: There was no significant difference in discourse participation and performance between participants with and without TBI. Individuals with and without TBI mostly talked about the task, gave thesis propositions, offered the possible function of the object, and gave rationales for their decisions. These may be obligatory (not optional) elements of problem-solving discourse. Individuals without TBI used significantly more tangential and unrelated talk, which may be indicative of more frequent and successful attempts to engage in social chat, even in a goal-driven activity. Conclusions: Competent discourse participation and performance is possible for individuals with TBI when they engage in meaningful interactions with friends. Problem solving may be a useful therapy genre for maximising communication outcomes of individuals with TBI, as it encourages the involvement of friends and elicits social chat as well as other creative language options.