CAR T-cells are autologous T-cells transduced with a chimeric antigen receptor which targets the modified T-cell against a specified cancer antigen. Anti-CD19 CAR T-cells currently represent transformational therapy for relapsed/refractory aggressive B-cell lymphomas where durable remissions can be induced in patients with previously incurable chemotherapy-refractory disease. Three anti-CD19 CAR T-cells are currently Food and Drug Administration and European Medicines Agency approved or in advanced-stage development: axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel. Although all targeting CD19 on the surface of malignant (and healthy) B-cells, these products differ from one another in multiple ways including construct, manufacturing, dose, design of pivotal clinical trials, and toxicity profile. Efficacy and safety data for anti-CD19 CAR T-cell therapy in aggressive B-cell lymphomas will be reviewed, as well as novel CAR T-cell designs and strategies for overcoming treatment resistance.