The graft-versus-leukemia (GVL)-effect achieved by donor-derived T cells arising from transplanted allogeneic hematopoietic stem cells or given as donor-leukocyte infusions (DLI) after allogeneic transplant, demonstrates that donor-derived T cells can eradicate B-lineage malignancies. However, graft-versus-host-disease (GVHD) occurring after allogeneic hematopoietic stem-cell transplant (HSCT) or polyclonal DLI can limit the efficacy of these interventions. This toxicity can be avoided by using autologous T cells and/or tumor-specific cytotoxic T lymphocytes (CTLs). To generate antigen-specific T cells that can be derived from the allogeneic donor or the patient, we have genetically manipulated T cells to express a CD19-specific chimeric immunoreceptor. This renders T cells specific for CD19, a cell surface molecule found on B-lineage leukemia and lymphoma. This review will demonstrate the redirected specificity of CD19-specific T cells and implementation of clinical trials using these cellular agents.