Abstract: Objective　To investigate the clinical characteristics and genetic diagnosis of neonatal Wiskott-Aldrich syndrome (WAS). Methods　The clinical characteristics of 3 cases of WAS were analyzed. The WASP gene mutations was analyzed by Sanger sequencing method. The related literatures were reviewed to summarize the clinical characteristics, diagnosis, and prognosis of WAS. Results　All three cases of WAS had postnatal thrombocytopenia, accompanying platelet volume decrease. One case suffered from sepsis. Three cases did not suffer from eczema. Three cases were detected WASP homozygotic mutations, 2 cases had WASP nonsense mutations, and one case had WASP missense mutations. Their mothers also had heterozygous mutations at the corresponding loci, and were confirmed as carriers. Conclusions　Neonatal WAS often do not have typical triad, eczema, thrombocytopenia, and immunodeficiency. For neonatal with idiopathic thrombocytopenia, especially with the decrease of platelet volume, the WASP gene analysis should be performed to diagnose WAS.