A preparation of autologous T-cells engineered to express a chimeric antigen receptor (CAR) specific for the tumor-associated antigen (TAA) CD123 (interleukin-3 receptor alpha chain or IL3RA), with potential immunostimulating and antineoplastic activities. Upon administration, the autologous anti-CD123 CAR-T cells target and bind to CD123 expressed on the surface of tumor cells. This induces selective toxicity in CD123-expressing tumor cells. CD123, the alpha subunit of the IL-3 receptor, regulates the proliferation, survival and differentiation of hematopoietic cells. It is overexpressed on a variety of cancers, including myeloid leukemia, and the increased expression of CD123 on leukemic stem cells (LSCs) is associated with poor prognosis.