Objective: To assess longer-term social cognition after mild traumatic brain injury (mTBI) and to identify the sociodemographic and acute factors (mood, cognitive functioning, and symptoms) influencing social cognition. Method: Data were extracted for 121 adults who experienced a mTBI and completed the Emotion Evaluation and Social Inference Enriched tests of The Awareness of Social Inference Test (TASIT) 4 years postinjury. To identify early indicators of outcome, responses to the Hospital Anxiety and Depression Scale, Rivermead Post-Concussion Symptom Questionnaire, and CNS Vital Signs neurocognitive assessment conducted 1 month postinjury were also extracted. Social cognition scores were compared to age-matched TASIT norms (N = 121). Results: The mTBI group was significantly less able to interpret what people say and intend than norms, although the effect sizes were small (d = 0.43). There were 24.8% of people 4 years postmTBI and 9.9% of norms who experienced at least mild impairment in social inference. There were no significant differences between the mTBI group and norms for emotion evaluation. Poorer social inference 4 years after mTBI was significantly associated with lower cognitive flexibility and executive function (F = 2.57, df = 13,26, p = .02). Group differences remained after controlling for cognitive functioning (F = 104.59 df = 1,58, p = .001. Conclusions: These novel results suggest that adults postmTBI may experience social inference difficulties 4 years post-TBI that are not completely explained by cognitive difficulties. Further research is needed. (PsycINFO Database Record (c) 2019 APA, all rights reserved)