Necrotising soft tissue infections (NSTI) encompass multiple different conditions: necrotising cellulitis (dermis and subcutaneous fat), necrotising fasciitis (primarily fascia, +/- muscle), necrotising myositis (primarily muscle, +/- fascia). NSTI name is based on clinical features rather than surgical/pathologic findings and characterised by fulminant tissue destruction, systemic signs of toxicity, high mortality. Necrotising fasciitis has three types. Type I (polymicrobial) is caused by a combination of aerobic and anaerobic bacteria; commonly at least anaerobe (bacteroides, clostridium) with Enterobacteriaceae (e.g. E.coli, enterbacter, klebsiella, proteus) and with one or more facultative anaerobic streptococcus other than strep pyogenes. This type has radiological evidence of gas in the tissues. Type II (monomicrobial) is classically caused by staphylococcus aureus, streptococcus pyogenes, clostridium species, vibrio species, aeromonas hydrophila. Type III is caused by Clostridium. The incidence of necrotising fasciitis is 4 per million people The risk factors associated with developing NSTI are breach in skin barrier (e.g. surgery, trauma), immunosuppression, malignancy, diabetes, peripheral vascular disease, obesity and alcohol abuse. The management relies primarily on radical surgical debridement and triple antibiotic therapy. Occasionally, patients may require amputation to control the sepsis. Intravenous immunoglobulins may help to neutralise streptococcal toxins, and boost antibody levels, thus leading to passive immunity. Hyperbaric oxygen may also be beneficial in reducing mortality and morbidity associated with NSTI.