OBJECTIVE: To identify the most common gait abnormalities presenting after traumatic brain injury (TBI) and quantify their incidence rate. DESIGN: Case series. SETTING: Biomechanics laboratory. PARTICIPANTS: A convenience sample of 41 people with TBI receiving therapy for gait abnormalities, and a sample of 25 healthy controls. INTERVENTION: Three-dimensional gait analysis. MAIN OUTCOME MEASURES: Spatiotemporal, kinematic, and kinetic data at a self-selected walking speed. RESULTS: People with TBI walked with a significantly slower speed than matched healthy controls. There was a significant difference between groups for cadence, step length, stance time on the affected leg, double support phase, and width of base of support. The most frequently observed biomechanical abnormality was excessive knee flexion at initial foot contact. Other significant gait abnormalities were increased trunk anterior/posterior amplitude of movement, increased anterior pelvic tilt, increased peak pelvic obliquity, reduced peak knee flexion at toe-off, and increased lateral center of mass displacement. Ankle equinovarus at foot-contact occurred infrequently. CONCLUSIONS: People with TBI were found to have multijoint gait abnormalities. Many of these abnormalities have not been previously reported in this population.