Chimeric antigen receptor (CAR) T cells are genetically engineered autologous cells that express an activating receptor targeted towards one or more tumoral antigens. After ex vivo production and re-infusion, they are able to proliferate in the host and to recognize and kill tumor cells. Together with checkpoint inhibition, this new therapy is already being celebrated as a major medical breakthrough in recent years, due to the substantial benefit observed in clinical trials with patients with chemotherapy-refractory B‑cell malignancies. These results have led to the recent approval of two CAR T‑cell products by the Food and Drug Administration (FDA) in the United States. The list of targetable antigens and possible indications is continuously being expanded, as are the modifications to the CAR structure and the final cell products currently under investigation. In some patients, CAR T‑cell therapy may lead to substantial toxicity including the cytokine release syndrome (CRS). In summary, CAR T‑cell therapy has already provided clinical benefit to patients with B‑cell malignancies unresponsive to conventional treatment. Yet, the therapy is still in an early stage of development, and the many opportunities for improvement in its various aspects as well as its future role in relation to conventional therapy will set the pace in the field of hematology for the next years or even decades.