Introduction Necrotizing fasciitis is a rare condition with a mortality rate of around 34%. It can be mono- or polymicrobial in origin. Monomicrobial infections are usually due to group A streptococcus and their incidence is on the rise. They normally occur in healthy individuals with a history of trauma, surgery or intravenous drug use. Post-operative necrotizing fasciitis is rare but accounts for 9 to 28% of all necrotizing fasciitis. The incidence of wound infection following saphenofemoral junction ligation and vein stripping is said to be less than 3%, although this complication is probably under-reported. We describe a case of group A streptococcus necrotizing fasciitis following saphenofemoral junction ligation and vein stripping. Case Presentation A 39-year-old woman presented three days following a left sided saphenofemoral junction ligation with long saphenous vein stripping at another institution. She had a three day history of fever, rigors and swelling of the left leg. She was pyrexial and shocked. She had a very tender, swollen left groin and thigh, with a small blister anteriorly and was in acute renal failure. She was prescribed intravenous penicillin and diagnosed with necrotizing fasciitis. She underwent extensive debridement of her left thigh and was commenced on clindamycin and imipenem. Post-operatively, she required ventilatory and inotropic support with continuous veno-venous haemofiltration. An examination 12 hours after surgery showed no requirement for further debridement. A group A streptococcus, sensitive to penicillin, was isolated from the debrided tissue. A vacuum assisted closure device was fitted to the clean thigh wound on day four and split-skin-grafting was performed on day eight. On day 13, a wound inspection revealed that more than 90% of the graft had taken. Antibiotics were stopped on day 20 and she was discharged on day 22. Conclusion Necrotizing fasciitis is a very serious complication for a relatively minor, elective procedure. To the best of our knowledge, this is the first report in the English-language literature of this complication arising from a standard saphenofemoral junction ligation and vein stripping. It highlights the need to be circumspect when offering patients surgery for non-life-threatening conditions.