Here we reported a 56 year-old female who was referred for F-18 FDG PET/CT imaging due to general weakness and hypercalcemia. The fused PET /CT images revealed gross skeletal muscle uptake of F-18 FDG. Although a variety of factors may result in diffuse skeletal muscle uptake of F-18 FDG, the laboratory findings including elevated serum creatine kinase and myoglobinemia represent an unusual case of rhabdomyolysis.