A 5-year-old girl was treated for 4 years based on a diagnosis of immune thrombocytopenia (ITP). When she presented for a second opinion, she met all criteria for ITP except that inspection of her peripheral blood smear showed large platelets with a complete lack of granulation, indicating a diagnosis of gray platelet syndrome (GPS), confirmed by electron microscopy .The name GPS comes from the gray appearance of the platelets as a result of the absence of a-granules. GPS is due to mutations in NBEAL2, which encodes for the neurobeachin-like 2 (NBEAL2) protein, a member of the family of BEACH (BEige And Chediak-Higashi) domain-containing proteins on chromosome 3 (3p21). Patients with GPS have a predisposition to mucocutaneous bleeding and also to develop myelofibrosis. This case illustrates the importance of inspection of the blood smear before making a diagnosis of ITP.