Idiopathic thrombocytopenic purpura (ITP) is an organ-specific autoimmune disease characterized by the production of antiplatelet antibodies secreted by B cells resulting in enhanced destruction of platelets by macrophages. B cells have been demonstrated to play a critical role in the genesis of ITP. Recently identified B cells activating factor of the TNF ligand family (BAFF) is essential in their physiology which can promote B cells development, survival, proliferation and maturation, then the secretion of more antibodies. In the pathological conditions of ITP, there is an overproduction of BAFF. Therefore, we propose that BAFF plays, at least in part, an important role in the pathogenesis of ITP and offers the opportunity to improve our therapeutic approach.