Introduction: Life-threatening mucormycosis has rarely been reported. Mortality rates of 50-100% make the earliest recognition of this highly fulminant infection, critical. Case Discussion: A 23-year-old male was referred from a semi-urban centre with 15-days of fever and a non-healing left thigh wound. He sustained a Gustilo-Anderson-IIIA open femur shaft fracture from a two-wheeler collision with a tree. Femoral nailing had been performed at the referring centre 2 days post-injury. His open wound kept discharging pus and he was referred for further management. Deeper questioning from parents revealed the patient's history of consuming weight-gain dietary supplements at his local gymnasium. His left thigh was grossly swollen and tender with a large 30x40cm black-grey, necrotic mass with powdery scales exposing underlying muscles. Repeated swabs revealed no significant growths and he deteriorated rapidly despite broad-spectrum antibiotics. Urgent multidisciplinary (orthopaedic-medicine-microbiology) discussions resulted in microbiologist-led sampling from the lesion's edge. This revealed broad, branching, irregular and septae tangles of fungal hyphae of mucormycosis. Liposomal Amphotericin-B therapy was immediately initiated and maintained (5mg/kg/day) for 2 weeks. Repeated aggressive surgical debridements complemented this. The patient’s condition improved dramatically. A large split-skin graft was then done over granulating tissue. After 6 weeks of stay, the patient went home walking. Serial follow-ups continued to show excellent improvements with good graft-take at 2 years. Conclusion: Mucormycosis presents as a rare, life-threatening infection. Clinical suspicion is warranted in potentially immunosuppressed patients and contaminated wounds. Specific medical and radical surgical treatment can make the difference between life and death.