A case of forearm compartment syndrome due to a minor trauma is reported. The severe clinical conditions due to a shock state lead to an initial misdiagnosis of clostridial myonecrosis. The patient, 68 y-old woman, was admitted to the intensive care unit of Authors' hospital for a traumatic injury of the right forearm. A diagnosis of gas gangrene due to clostridial myonecrosis was done and forearm amputation suggested. In spite of this indication a decompression fasciotomy of the forearm compartments was performed as well as a hyperbaric oxygene therapy. Since culture of necrotic tissue samples did not demonstrate any bacterial growth, the Authors decided to avoid amputation and perform a radial arteriovenous fistula to improve venous return and reduce distal edema and continuous bleeding, with a complete recovery within 40 days. Good evaluation of patient with suspected compartment syndrome means correct and not delayed treatment, avoiding invalidating outcome.