Necrotising soft-tissue infections occur in the soft tissue compartment consisting of the dermis, subcutaneous tissue, superficial fascia (fascia of Scarpa), deep fascia and muscle. Although this severe and acutely life-threatening infection has a low incidence, both GPs and specialists will see a necrotizing soft-tissue infection more than once during their career. The mortality related to necrotising soft-tissue infections has been halved during the past 15 years from nearly 40 to 20% due to adequate treatment. Laboratory examination and X-ray findings could be of added value, but the gold standard remains biopsy of the fascia and Gram staining. Treatment consists of prompt volume resuscitation in case of sepsis, administration of broad spectrum antibiotics and surgical debridement; this debridement should be as skin-sparing as possible. The use of hyperbaric oxygen therapy has remained a controversial issue, unless a patient has gas gangrene, caused by Clostridium species. A multidisciplinary treatment and admission to a tertiary intensive care unit are indispensable for the treatment of a septic patient with necrotizing soft-tissue infection.