A case of necrotizing fasciitis (NF) is described in a 46-year-old woman with recent onset systemic lupus erythematosus (SLE). Deep-tissue infections are more common in SLE patients on high-dose corticosteroids, but, to our knowledge, this is the second case described in association with SLE. Although NF may initially be difficult to diagnose, the presence of marked systemic symptoms out of proportion to the local findings should suggest the correct diagnosis. NF diagnostic criteria, treatment and prognosis are discussed.