Antinuclear antibodies (ANA) are found in the majority of patients with systemic lupus erythematosus (SLE). We report here the only documented case, out of a series of 38 patients, in which SLE was diagnosed in spite of the fact that we failed to demonstrate any type of autoantibodies. A 25-year-old black woman presented with 6 of the 11 criteria of the American Rheumatism Association for classification of SLE, between August 1984 and April 1985, i.e. malar rash, photosensitivity, arthritis, pleurisy and pericarditis, renal insufficiency and nephrotic syndrome, anemia and leukopenia. Renal biopsy revealed mesangial glomerulonephritis, tubulonephritis and many tubuloreticular inclusions in the capillary endothelium highly suggestive of SLE. Four ANA determinations were performed during the 8 months of observation which were all negative, as were all other antibodies (anti-nDNA, -Sm, -RPN, -Ro, -La). The outcome was very favourable under prednisone and cyclophosphamide. In the rare cases of ANA negative SLE (5-10%) photosensitive dermatitis is the prominent feature and renal or central nervous system involvement is less frequent. Those patients usually have other types of autoantibodies (especially anticytoplasmic) which was not the case in our patient. This indicates that the absence of autoantibodies does not rule out SLE.