Primary immune thrombocytopenia is an acquired autoimmune disorder caused by the production of antiplatelet antibodies. These autoantibodies opsonize platelets for splenic clearance, resulting in low levels of circulating platelets. The current case–control study aimed at detecting the frequency of interleukin-23 receptor rs1884444 single nucleotide polymorphism in Egyptian children with primary immune thrombocytopenia and its possible role as a genetic marker for disease risk. Interleukin-23 receptor rs1884444 single nucleotide polymorphism was studied in 50 patients with primary immune thrombocytopenia and 100 healthy age and sex-matched controls by polymerase chain reaction amplification of the target gene followed by allele-specific restriction enzyme digestion. Regarding the distribution of the genotypes of the interleukin-23 receptor rs1884444 polymorphism, no statistically significant difference was found between cases and control groups. The variant genotypes (GT/TT) frequency was 10% in primary immune thrombocytopenia cases versus 7% in the control groups [P value = 0.755, odds ratio (OR): 0.326, 95% confidence interval (CI): 0.099–1.076]. Similarly, no difference was found between acute and chronic cases. The variant genotypes GT/TT frequency was 10.7% in acute versus 9.1% in chronic primary immune thrombocytopenia (P value = 0.849). The variant genotypes GT/TT were not found to be a risk factor for acute primary (P value = 0.807, OR: 0.641, 95% CI: 0.16–2.563) or chronic primary immune thrombocytopenia (P value = 0.914, OR: 0.762, 95% CI: 0.153–3.797). Our study suggests the possibility that interleukin-23 receptor gene polymorphism may not contribute to the susceptibility of development of primary immune thrombocytopenia in Egyptian children.