Chronic myeloid leukemia (CML) is a form of chronic myeloproliferative disease(CMPD) with a well-defined genetic defect known as the Philadelphia (Ph)chromosome. The Ph chromosome is associated with a BCR-ABL fusion geneexpressed as an oncoprotein, Bcr-Abl kinase activity leads to uncontrolledproliferation of the malignant CML clone. With loss of differentiation the diseaseproceeds to the more aggressive accelerated and blastic phases.The treatment of chronic myeloid leukemia (CML) has been characterized inrecent years by some of the most remarkable achievements in the treatment ofcancer. Some of the best results obtained with allogeneic stem cell transplantation(SCT) have been reported in CML, and CML was probably also one of the firstmalignancies in which a biologic agent, interferon alpha (IFN-α), was able toeliminate the disease, substantiated by the achievement of a complete cytogeneticremission in a fraction of all patients treated. Most recently, the introduction ofImatinib mesylate represents one of the best examples of a target-specific therapythat has resulted in complete responses for the majority of patients with thisdisease. The evaluation of the outcome of treatment of adult Egyptian CMLpatients with Imatinib mesylate compared to the international results was done inthis study.