Little is known about social influences on long-term rehabilitation outcomes for traumatic brain injury, particularly social comparisons (i.e. self-evaluations relative to others). Patients in long-term rehabilitation (n = 31) completed assessments at baseline and 1 year. Self-reported social comparison orientation was comparable to existing samples and showed stability over 1 year; affective responses to comparisons (e.g. frustration) were less stable. Social comparison orientation and affective responses were related to baseline executive and psychosocial functioning (rs = 0.34–0.53) and predicted worse impairment and depression at 1 year (ds = 0.67, 1.39). Greater attention to comparisons in long-term rehabilitation could improve outcomes.