Background: Primary immune thrombocytopenia (ITP) is one of the most common autoimmune diseases characterized by low platelet count resulting from increased platelet destruction and impaired platelet production. The pathophysiology of ITP remains understood, and the study of polymorphism in different cytokine coding genes is important to understating the pathophysiology of the disease. This study aimed to evaluate the association between IL1β-31 and IL-1RA gene polymorphism in ITP. Subjects and methods: this is a case-control study conducted on 50(30 children and 20 adults) ITP patients and 60 age and sex-matched healthy controls. Genotyping of IL1β-31and IL-1RA gene polymorphism was performed using Restriction Fragment Length Polymorphism (RFLP-PCR) and detection of variable number tandem repeats. Results: the present study showed a significant association between IL1β-31 and IL-1RA gene polymorphism and ITP development. The mutant homozygous and heterozygous IL1β-31 and IL-1RA genotype and the mutant allele showed higher frequency compared to the control group and are associated with ITP susceptibility (odd ratio >1), p-value ( |