BAFF is a ligand belonging to the tumor necrosis factor (TNF) family, has a crucial role in B cells development, survival, and immunoglobulin-production through binding to its three receptors, BCMA, TACI and BAFFR. Defects in the production of BAFF and/or expression of its receptors associated with human immunopathologies. ITP is isolated thrombocytopenia with no clinically apparent associated conditions or other causes of thrombocytopenia, classified to acute and chronic. In the present study BAFF gene polymorphisms expression at positions (-871C>T, -2701 T>A and -2841T>C) of 5` regulatory region in chronic ITP patients were determined with RFLP-PCR assay in 40 patients with chronic ITP as well as 30 normal subjects as a control group. The frequency of the -871C>T polymorphism genotypes among chronic ITP patients were 17.5% had a (CC) genotype while 82.5% had T allele (57.5% were heterozygous C/T & 25% were homozygous T/T) while among the control group 80% had a (CC) genotype and 20% had T allele (all were heterozygous C/T). As regard -2701T>A polymorphism was 17.5% had a (TT) genotype while 82.5% had A allele (35% were heterozygous T/A & 47.55% were homozygous A/A) while among the control group 90% had (TT) genotype and 10% had A allele (all were heterozygousT/A). Regarding -2841T>C polymorphism was 42.5% had (TT) genotype while 57.5% had C allele (47.5% were heterozygous T/C & 10% were homozygous C/C) while among the control group 90% had a homozygous (CC) genotype and 10% had C allele (all were heterozygous T/C). The difference between chronic ITP patients and control subjects in all polymorphisms was statistically significant with higher expression of T allele, A allele and C allele respectively in ITP patients than control group. All polymorphisms were associated with increased risk of chronic ITP with odds ratio 18.857, 42.429 and 12.176 respectively. In all polymorphisms there was neither significant association nor significant correlation between BAFF gene polymorphisms and age, sex, duration of disease; clinical data; laboratory data & response to treatment. In conclusion BAFF gene polymorphisms expression had a significant association with chronic ITP disease. Also BAFF gene polymorphisms are neither involved in clinical & laboratory presentation of patients of chronic ITP nor associated with treatment outcome of disease.