A preparation of autologous T-lymphocytes engineered to express a chimeric antigen receptor (CAR) that is nanobody-based and specific for the two tumor-associated antigens (TAAs) cluster of differentiation 19 (CD19) and CD20, with potential immunostimulating and antineoplastic activities. Upon administration, the autologous anti-CD19/CD20 bispecific nanobody-based CAR-T cells target and bind to CD19- and CD20-expressing tumor B-cells. This induces selective toxicity in tumor B-cells expressing these TAAs. Both CD19 and CD20 are B-cell-specific cell surface antigens overexpressed in B-cell lineage malignancies. Targeting both CD19 and CD20 may prevent tumor cell antigen escape and relapse.