Progress in our understanding of basic immunology along with the advent of bioengineering technologies have made possible the production of human T-cells expressing Chimeric Antigen Receptors (CAR T-cells). These CAR T-cells are designed to target specific antigens presented by cancer cells. Once CARs are bound to these antigens, CAR T-cells get activated and can initiate potent anti-tumor effects. We will here overview the bioengineering advances which made possible the clinical application of CAR T-cell therapy. We will review the data to date regarding anti-CD19 CAR T-cell therapy for acute lymphoblastic leukemia, non-Hodgkin lymphomas, and chronic lymphocytic leukemia. Besides CD19, CAR T-cells directed against the B-cell maturation antigen have also shown encouraging results to treat patients with refractory multiple myeloma. The more limited body of clinical research in the field of solid tumors will also be reviewed. Moreover, we will elaborate on the main toxicities of limitations of CAR T-cell therapy, namely cytokine release syndrome and neurotoxicity. While enjoying an undeniable hype, CAR T-cell therapy bears significant limitations. We will conclude by exposing the possible approaches to make CAR T-cells safer and more efficient beyond the CD19 target.