Objective: Problems with language, pragmatic communication, behavior, and social competence are common following childhood TBI. Few studies have examined relationships among these areas of functioning. Method: At 38 months post-injury, parents of children with orthopedic injury (OI; n =75, injury age = 5.11 years), complicated mild to moderate TBI (n =49, injury age = 5.01 years), or severe TBI (n = 19, injury age = 4.95 years) completed the Child Communication Checklist- 2 (CCC-2). The CCC-2 assesses pragmatic communication (e.g., communication of interests, non-verbal communication) and structural language (e.g., syntax, semantics). At 81 months post-injury, parents (70 OI, 41 complicated mild to moderate, and 16 severe) completed the Home and Community Social Behavior Scales (HCSBS) Social Competence subscale and the Child and Adolescent Functional Assessment Scale (CAFAS), an assessment of post-TBI behavioral functioning. Results: The severe TBI group evidenced significantly more problems with structural language, pragmatic communication, and social competence compared to the OI and complicated mild to moderate groups. Behavior (CAFAS) was poorer in the severe compared to the OI groups. Severe TBI and lower CCC-2 Interests and Social Relations (poorer abilities) was associated with lower HCSBS (poorer competence) with a medium to large effect size (R2 = .48). Severe injury, lower CCC-2 Interests, and older injury age was associated with higher CAFAS (more problems) with a medium effect size (R2 = .31). Conclusion: Childhood TBI may result in structural language and pragmatic communication weaknesses, the latter associated with poorer long-term social competence and behavior. These findings support the utility of post-TBI interventions that target pragmatic communication.