Background: Systemic lupus erythematous is an autoimmune disease of multifactorial etiology with genetic predisposition. Its pathogenesis involved more than 100 genes. CD24 gene can mediate various functions such as their costimulatory activity in the clonal expansion of T cells. The single nucleotide polymorphism, resulting in a non-conservative replacement of alanine to valine (CD24v) precedes immediately GPI anchorage site (position ω-1), determines CD24 loss activity. CD24v has been associated with multiple sclerosis and systemic lupus erythematous in other populations. Objective: To find the presence of CD24v in Mexican patients with systemic lupus erythematous.  Material and method: A study of fenotyping of CD24v included 65 subjects, 32 cases (systemic lupus erythematous): 28 women and 4 men; and 32 controls: 9 women and 23 men; cases and controls from patients with systemic lupus erythematous in National Medical Center 20 de Noviembre ISSSTE, Mexico City, services of Clinical Immunology and Rheumatology.  Results: In cases, 19 patients had a wild homozygous genotype, 12 were heterozygous and only one patient showed homozygous polymorphism. In controls, 17 showed wild heterozygous genotypes; 14 were heterozygous and 1 was found to be polymorphic homozygote. With odds ratio: 0.84 and chi cuadrada of 0.17; therefore there was no statistically significant difference.  Conclusions: Study population showed that there is no statistically significant difference between systemic lupus erythematous cases and controls with respect to the presence of CD24v.