Chronic Granulomatous Disease (CGD) is a rare primary immunodeficiency due to a defect in one of the NADPH oxidase complex subunits; 70 % of cases are X-linked, due to a CYBB mutation, resulting in defective production of gp91PHOX. Female carriers of X-linked CGD have previously been considered to be unaffected. It is increasingly recognized that they may suffer from similar problems to CGD patients. This review will examine the literature about clinical manifestations of disease in X-linked carriers of CGD.