Desmoplastic Fibroma is a rare, slowly progressive, and aggressive benign bone tumour. It is made up of spindle cells with minimal atypia and abundant collagen production. It occurs most commonly in the mandible, followed by the femur and pelvis. However, because it is so rare and presents differently with each patient, the diagnosis and management of these lesions still varies from case to case. We present a case of an otherwise healthy Malaysian Air Force officer who presented with left facial swelling accompanied by severe pain and trismus. Patient was thought to have osteomyelitis of the left mandible based on clinical and radiological findings. However, despite multiple debridement, IV antibiotic therapies, incisional biopsies and radiological investigations, patient’s symptoms persisted. Finally, after 4 years, we landed on a provisional diagnosis of Desmoplastic Fibroma of the mandible bone and the adjacent muscles of mastication. We hope to highlight our experience in the management of this case so it will aid in the betterment of approach in such cases in the future.