Guillain-Barre syndrome (GBS) has been rarely reported as a presenting manifestation of systemic lupus erythematosus (SLE). We describe a 23-year-old patient with SLE who presented with GBS. He developed progressive ascending motor paralysis but also had pulmonary disease, proteinuria, and hypoalbuminemia. Serologic studies revealed ANA and antibodies to double stranded-DNA. Electromyographic and nerve conduction studies were suggestive of acute inflammatory demyelinating polyneuropathy, and a kidney biopsy specimen showed membranous glomerulonephritis. Treatment with corticosteroids and plasmapheresis resulted in clinical improvement of the neurological illness. The renal disease progressed despite prednisone and was eventually treated with hemodialysis. The neurologic disease did not recur.Auto-antibodies reactive with neural tissue and immunological crossreactivity between auto-antibodies in SLE and neural tissue antigens may occur. Complement fixing antibodies to nerve and kidney in patients with GBS and membranous glomerulonephritis, point to a common pathogenic relationship. Such antibodies may be seen in patients with SLE. The increased susceptibility to infection caused by immunosuppression may make patients with SLE susceptible to GBS. Plasmapheresis and corticosteroids, as in our patient, plus i.v. immunoglobulins and cyclophosphamide has brought good results in patients who have SLE with GBS.