Blastic phase (BP), the terminal phase of chronic myeloid leukemia (CML), can occur in any of the hematopoietic lineages. Extramedullary blastic crisis (EBC) is a rare form of blastic crisis, which has an extremely poor prognosis. As the tyrosine kinase inhibitor (TKI), Dasatinib is a more effective treatment drug than Imatinib and Nilotinib for this type of CML, because it has greater potency and penetrates through the blood-brain barrier to reach the cerebrospinal fluid (CSF). This report examines the case of a 22-year-old woman with CML, who successively suffered from monocytic blast crisis, lymphoid blast crisis, and central nervous system EBC. She had an overwhelmingly positive response to taking Dasatinib and eventually achieved lasting complete remission.