The presence of antinuclear antibodies (ANA) in serum is generally considered a decisive diagnostic sign of systemic lupus erythematosus (SLE). Ten patients with clinical signs of disease but persistent negative tests for ANA are examined in this study. Hair fall, Raynaud's phenomenon and recurrent oral ulcers were common in the ANA-negative group. ANA-negative SLE seems to be a subgroup of SLE that has not previously been given adequate attention.