B-cell activating factor (BAFF) plays a crucial role in B-cell development, survival andimmunoglobulin production. Excess BAFF results in the rescue of self-reactive B cells fromanergy, and the rescue of autoreactive T cells from the suppressing effect of dendritic cells, thusimplicating a role in the development of autoimmunity. The aim of this study was to evaluateBAFF and its receptor (BAFF–R) mRNAs expression in patients with idiopathicthrombocytopenic purpura, and also to study the potential association of their expression withvariation in disease severity, chronicity and response to treatment. Evaluation of BAFF andBAFF-R expression was done using quantitative real-time polymerase chain reaction (qRTPCR),in 79 ITP patients as well as 20 age- and sex-matched control volunteers. The medianexpression level of BAFF and of BAFF-R in ITP patients was significantly higher compared tothe control group. Children had a significantly lower mean BAFF expression level compared toadults with ITP. Female patients had a significantly higher mean BAFF-R expression levelcompared to male patients. Patients with active ITP had a significantly higher BAFF expressioncompared to those in remission and those of control group. Mean expression level of BAFF-Rwas significantly higher in Patients with active ITP and in those in remission when each wascompared to the control group. BAFF-R expression was significantly higher in steroid treatedpatients compared to untreated patients. A significant positive correlation was found betweenBAFF and BAFF-R mRNA expression levels. BAFF expression was positively correlated withthe median age of patients at sampling time and at diagnosis. Elevated BAFF expression inpatients with active ITP indicates its possible role in the pathogenesis of ITP. Hence, selectiveantagonistic targeting of BAFF or BAFF-R in ITP patients with high levels of BAFF expressionmight be considered as a novel therapeutic strategy.