Wiskott-Aldrich syndrome (WAS) is a rare X-linked immunodeficiency characterized by various clinical phenotypes. We report the case of a 3-year-old immigrant boy presenting with persistent infant-onset thrombocytopenia treated for refractory immune thrombocytopenic purpura. Sequence analysis confirmed the diagnosis of WAS. The patient responded neither to IV infusions of immunoglobulin (Ig) nor a thrombopoietin receptor agonist and is currently planned for stem cell transplantation. Raised awareness is thus vital of this potentially misdiagnosed and lethal disorder. The diagnosis of WAS should be considered in all males with infant-onset immune thrombocytopenic purpura-like features, especially, if mean platelet volume is decreased (<7 fL) and good increment to platelet transfusions are evident.