© 2016, © The Academy of Spinal Cord Injury Professionals, Inc. 2016. Objectives: To study the patterns of weight change after spinal cord injury (SCI) and identify associated risk factors. Study design: Cohort study. Setting: Sixteen Spinal Cord Injury Model Systems (SCIMS), USA. Participants: One thousand and ninety-four individuals with an SCI who were entered into the SCIMS and had a 1-year follow-up between October 2006 and November 2012. Intervention: Not applicable. Outcome measure: Change in body mass index (BMI) during the first year of injury. Height and weight were assessed during inpatient rehabilitation and 1 year after injury. Results: Mean BMI decreased from 26.3 to 25.8 kg/m² during the first year after SCI (mean change: −0.5 kg/m² (standard deviation: 3.58)). Weight loss was mainly observed among individuals classified as overweight or obese during rehabilitation (n = 576) with a BMI decrease of 1.4 kg/m², which varied significantly by sex, education, neurological level, and the presence of vertebral injury. Weight gain was noted among individuals classified as underweight or normal weight during rehabilitation (n = 518) with a BMI increase of 0.5 kg/m², with the greatest increase among individuals of Hispanic origin (1.2 kg/m²), other marital status (1.2 kg/m²), age group 31–45 years (1.1 kg/m²), with less than high school education (1.1 kg/m²), without spinal surgery (0.9 kg/m²), and with motor functionally incomplete injury (0.8 kg/m²). Conclusion: Our findings suggest that strategies for weight management should be addressed after a SCI to ameliorate the potential for unhealthful weight change, particularly among at-risk groups.