Patients sustaining traumatic injuries are at risk for development of rhabdomyolysis. The effect of obesity on this risk is unknown. This study attempted to characterize the role of obesity in the development of rhabdomyolysis after trauma. This was a retrospective review of all trauma patients with creatine kinase (CK) levels admitted to the surgical intensive care unit (SICU) at a Level I trauma center from February 2011 until July 2013. Patients were divided based on their body mass index (BMI): overweight/obese group with BMI 25 kg/m(2) or greater and nonoverweight/obese group with BMI less than 25 kg/m(2). Primary outcome was CK greater than 10,000 U/L. During the 30-month study period, 198 trauma patients with available CK levels were admitted to the SICU. The majority (27.8%) of patients were involved in a motor vehicle collision. There were 96 patients (48.4%) with BMI 25 kg/m(2) or greater and 102 (51.5%) with BMI less than 25 kg/m(2). There was no difference in creatinine levels between the two groups (1.5 ± 1.2 mg/dL vs 1.5 ± 1.4 mg/dL, P = 0.83). BMI 25 kg/m(2) or greater was independently associated with the development of CK greater than 10,000 U/L (14.6 vs 4.9%; adjusted odds ratio, 3.03; P = 0.04). Patients with BMI 25 kg/m(2) or greater are at a significantly higher risk for rhabdomyolysis after trauma. Aggressive CK level monitoring to prevent rhabdomyolysis in this population is strongly encouraged.