Glanzmann`s thrombasthenia is a rare autosomal recessive inherited bleeding disorder associated with abnormal clot retraction and a normal platelet count. This disorder is characterized by the inability of the aggregation of platelets in response to the stimulation of ADP, epinephrine or collagen but it can aggregate by ristocetin. The primary feature of this disorder is the deficiency or abnormality of the glycoprotein IIb/IIIa complex, one of the major surface proteins of the platelet membrane participating in the aggregation between the platelets with fibrinogen. This disorder can be detected by the analysis of the glycoprotein Ilb/IIIa complex on the platelet membrane of the patient by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We experienced one case of Glanzmann's thrombasthenia with iron deficiency anemia in a 16-year-old male, who had suffered from frequent gingival bleeding, epistaxis, and easy bruising. After platelet function test and SDS-PAGE, we diagnosed him as Glanamann`s thrombasthenia with iron deficiency anemia due to chronic blood loss.