Numerous studies have examined the effect of genetic variations in the toll-like receptor 9 (TLR9) on the development of systemic lupus erythematosus (SLE). An allele-specific PCR technique was employed to analyze the genetic variation in the study participants in a cohort of SLE (n=103) and healthy controls (n=101) from the Golestan region of northern Iran. Our study revealed no statistically significant variations in genotype and allele distribution between individuals with SLE and the control group. When analyzing the genotype frequency for rs352139, no significant association was observed between the GA genotype and the AA genotype in relation to the risk of developing SLE, using the GG genotype as the reference. These findings indicate that the TLR9 rs352139 SNP does not play a significant role in determining susceptibility to SLE in the Golestan province of Iran.