Objective: To describe the epidemiology of wheelchair-related falls in spinal cord injury (SCI). Design: Prospective cohort study with baseline data collection and monthly follow-up for 12 months. Setting: 3 Department of Veterans Affairs SCI centers and 1 SCI support clinic. Participants: Veterans with nonprogressive SCI or disorders who use a wheelchair as a primary form of mobility. Interventions: Not applicable. Main Outcome Measures: Wheelchair falls and tips and injurious falls. Results: Preliminary data from the initial 655 subjects enrolled in the study are reported, of whom 339 have completed the 12-month follow-up to date. 25% of the subjects have reported wheelchair falls during the follow-up period, and just under half of those reported multiple falls. 12% of all subjects reported injurious falls. Injuries ranged from minor cuts or abrasions to 1 fall-related death and 4 subjects with fall-related fractures. Factors typically associated with falls in ambulatory nonwheelchair users (eg, older age, greater limitations in physical activity, cognitive impairment, and environmental factors such as poor lighting) do not appear to be associated with wheelchair-related falls in our sample. In contrast, our preliminary data suggest that wheelchair-related falls in SCI are more common with younger age, higher activity level and surrogates for greater activity and/or wheelchair use (eg, paraplegia vs quadriplegia, higher FIM scores), and with use of manual versus power wheelchairs. Conclusions: This study provides epidemiologic data that should be valuable in future development of models for predicting wheelchair falls and fall-related injuries in people with SCI, and in suggesting health-related practices that could be modified to decrease wheelchair-related falls and associated injuries.