Abstract: Fifty-seven patients suffering from systemic lupus erythematosus with different clinical features were studied from various aspects of immunological abnormalities, including anti-nuclear antibodies; anti-DNA; anti-Sm (Smith's antigen); and, other extractable nuclear antigens. The tests employed were microhemagglutination, counter immunoelecterphoresis, and radio immunoassay (RIA). The comparison between the two techniques for detectiong anti-DNA titers showed a significant correlation between them. There was also a significant positive correlation between the presence of anti-DNA and lupus nephritis (P>0.05). However, lupus nephritis has a negative association with anti-Sm. We will discuss anti-Sm in SLE patients that may have an inhibitory effect on -developing the lupus nephritis. The association of anti-Sm in SLE may help the physicians to prognose the disease and manipulate the treatment.