Wiskott-Aldrich syndrome is a rare X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, and an increased incidence of autoimmunity and malignancies. The incidence of this rare X-linked primary immuno-deficiency disorder is approximately one to four cases per 1,000,000 live male births. The disease is caused by mutations in the WAS gene that is involved in actin polymerization and associated coupling of receptor engagement, signaling events, and cytoskeletal rearrangement.  The diagnosis of a WAS-related disorder is established in a male proband with both congenital thrombocytopenia (<70,000 platelets/mm3) and small platelets, in addition to at least one of the following features: eczema, recurrent bacterial or viral infections, autoimmune disease(s), malignancy, reduced WASP expression in a fresh blood sample, abnormal antibody response to polysaccharide antigens and/or low isohemagglutinins, or positive maternal family history of a WAS-related disorder. Identification of a hemizygous WAS pathogenic variant on molecular genetic testing is necessary to confirm the.  As a screening tool in all cases of suspected WAS is used the flow-cytometry analysis of WASp expression. The quantification of intra-cytoplasmic WASp expression serves as a rapid and inexpensive screening test for WAS. An oldest method but quite effective is Single-strand Conformational Polymorphism (SSCP) that offers a sensitive but inexpensive, rapid, and convenient method for determining mutations of WAS gene. The distribution of mutations is uneven, with most occurring in the first four exons of the N terminal region.  For those cases in which the diagnosis is still under consideration, sequencing of the WAS gene is required. This typically includes sequencing of the coding regions as well as the intron and exon boundaries of the WAS gene.Prenatal evaluation of high-risk pregnant women with Wiskott-Aldrich syndrome may be accomplished by karyotyping, gene analysis, and Wiskott-Aldrich syndrome protein detection using cord blood.  In conclusion, despite the rarity of WAS, it is necessary continuously to make impressive strides in the strategies used to diagnose WAS.