Necrotising fasciitis (NF) is a rare infection of the subcutaneous tissue, known to be rapidly progressive and potentially fatal. Patients with systemic lupus erythematosus (SLE) may be predisposed to this condition, and early clinical recognition can be difficult. We report a case of necrotising fasciitis in a 26-year-old woman with SLE. She presented with painful swelling of her left leg, then developed clinical features of septic shock. Emergency debridement was performed. Intraoperative findings revealed NF and cultures grew Pseudomonas aeruginosa. The patient survived after a lengthy hospital admission, following several further debridements complicated by recurrent chest sepsis and multiorgan failure. We also review and discuss the published cases of NF in SLE patients.