Rhabdomyolysis is a clinical syndrome with the potential to cause cardiac arrhythmias, renal failure, and even death. Currently, there are no studies regarding risk factors for developing post-operative rhabdomyolysis (POR) after spinal fusion surgeries. Our objective was to study risk factors associated with, and to develop a decision-making framework for post-operative rhabdomyolysis after spinal fusion surgery.We performed a retrospective cohort study of all spinal fusions of three or more levels over 2.25 years by a single surgeon at two centers. POR was defined as a creatine phosphokinase (CPK) greater than 2000 IU/L.76 surgical procedures on 72 patients were identified. Rate of POR in our cohort was 22% (17/76). Male sex was associated with POR (In spinal fusions, increasing the number of lateral levels fused via transpsoas approach, and male gender, predispose patients to increased risk of POR in those without a second surgery within seven days, and in those with a simultaneous posterior fusion.