Background: Emphysematous osteomyelitis is a rare but fatal condition, caused by gas-forming bacteria. We reported a rare case of emphysematous osteomyelitis of left femur in a 27-year-old diabetic male, diagnosed on Tc99m methylene diphosphonate (MDP) single photon emission computed tomography-computed tomography (SPECT-CT) scintigraphy. The pattern of uptake in emphysematous osteomyelitis on Tc99m MDP SPECT-CT scintigraphy was not reported previously. Case Presentation: A 27-year-old diabetic male patient presented with history of pain in left thigh and fever for 10 days. He was referred to nuclear medicine department for Tc99m MDP bone scan. He had no history of trauma or surgery, and his radiograph of left femur was unremarkable at presentation. Tc99m MDP SPECT-CT scintigraphy showed abnormal uptake in femur with intraosseous air, pathognomic of emphysematous osteomyelitis. Further imaging by magnetic resonant imaging (MRI) showed edematous changes in the musculature of left thigh with marrow replacement changes in left femur favoring the diagnosis of emphysematous osteomyelitis. However, no bacterial growth was detected on blood culture due to prior administration of intravenous antibiotics. Conclusion: Tc99m MDP SPECT-CT scintigraphy is helpful in diagnosis of such rare conditions like emphysematous osteomyelitis, in addition to common pathologies of bone. Furthermore, this report is helpful for nuclear physicians to know about the pattern of uptake on planner bone scan and SPECT-CT images in such a rare infection of bone, by gas forming bacteria.