Background: There is growing evidence of impaired social cognition in individuals with traumatic brain injury (TBI). Social cognition tests, however, place demands on domain-general cognitive functions such as auditory working memory, so that test scores might reflect the influence of these factors on test performance rather than domain-specific social cognition impairments. As an alternative, we examined conversations of adolescents with TBI for evidence of cognitive state terms. Methods and Procedures: Participants were 16 adolescents with TBI, who were divided into two groups (TBI-Low and TBI-High) based on scores on a test of theory of mind (ToM), and 8 typically developing (TD) adolescents matched to participants in the TBI groups for age and race. Each participant completed a 3-minute conversation with a peer or researcher partner, and conversations were analysed to determine the number of cognitive state terms relative to total words produced. Outcomes and Results: The TBI-Low group expressed significantly fewer cognitive state terms and significantly fewer self- vs other-referenced terms than either the TBI-High or TD group. There was no significant difference between the TD and TBI-High groups. The findings were not related to generally impoverished language in the TBI-Low group, as the three groups were similar on measures of lexical diversity. Conclusions: The findings support the hypothesis that adolescents with TBI have domain-specific deficits in social cognition, beyond what might be accounted for by the cognitive demands of social cognition tests. Given the relation of social cognitive ability to important life outcomes, these skills should be included in the evaluation of individuals with cognitive-communication disorders after TBI.