© 2017 American Congress of Rehabilitation Medicine Objectives: To evaluate (1) the trajectory of resilience during the first year after a moderate-severe traumatic brain injury (TBI); (2) factors associated with resilience at 3, 6, and 12 months postinjury; and (3) changing relationships over time between resilience and other factors. Design: Longitudinal analysis of an observational cohort. Setting: Five inpatient rehabilitation centers. Participants: Patients with TBI (N=195) enrolled in the resilience module of the TBI Model Systems study with data collected at 3-, 6-, and 12-month follow-up. Interventions: Not applicable. Main Outcome Measure: Connor-Davidson Resilience Scale. Results: Initially, resilience levels appeared to be stable during the first year postinjury. Individual growth curve models were used to examine resilience over time in relation to demographic, psychosocial, and injury characteristics. After adjusting for these characteristics, resilience actually declined over time. Higher levels of resilience were related to nonminority status, absence of preinjury substance abuse, lower anxiety and disability level, and greater life satisfaction. Conclusions: Resilience is a construct that is relevant to understanding brain injury outcomes and has potential value in planning clinical interventions.