Necrotizing Fasciitis (NF) and sepsis shock is a rare disease in human caused by bacteria infection which is detrimental to patients. We report the diagnosis, progress, treatment and prognosis of patients with NF and sepsis shock caused by Aeromonas hydrophila (A. hydrophila). A 64 y old man was admitted for Gustilo type-iii B open fracture of the left tibia and fibula. Debridement and exopexy were carried out immediately after which he received liquid infusion and empirical antibiotic therapy in ICU. However, the condition became worse 24 h later and large extensive necrosis of the fascia and surrounding tissue was observed and the patients was in hypodynamic septic shock. Therefore, the infected limb was amputated and in the meantime, culture test for the necrotic tissue revealed presence of A. hydrophila and Klebsiella. Piperacillin and Tazobactam were applied to the patient for eliminating klebsiella and A. hydrophila respectively. Eleven weeks after admission, all blood biochemical parameter recover to normal and the patient was discharged. We present a rare case of A. hydrophila NF and sepsis shock in an elderly patient and suggest that resecting debridement of necrotic fascia and even limb-amputation is required for successful treatment.