Background: Glanzmanns Thrombasthenia (GT) is a GPIIb/IIIa platelet surface receptor condition that is defined by a lack of platelet aggregation, either qualitatively or quantitatively. This receptors physiological function is to bind various sticky plasma proteins that aid platelet adhesion and aggregation, ensuring the development of thrombus at sites of vascular damage. Patient of GT typically presents with menorrhagia, easy bruising, epistaxis, and gum bleeding.Prolonged untreated or unsuccessfully treated hemorrhagia associated with GlanzmannsThrombasthenia may be life threatening. Case Description: A 12 years old girl presented with bleeding since 12 days with complaints of generalized weakness. The patient was then investigated to find the cause of puberty menorrhagia. Several blood investigations were performed, and a final diagnosis of Glanzmanns Thrombasthenia was made. Objective:To highlight a rare case of Glanzmanns Thrombasthenia with β-Thalassemia trait in a 12 years old girl with puberty menorrhagia.