It is now widely accepted that current standard therapy does not lead to cure for the majority of patients with B-cell malignancies. In the search for novel treatment modalities and with the discovery of tumor-antigen--derived peptides recognized by T cells in the context of major histocompatibility complex class I and II molecules, active and passive immunotherapy has moved to center stage once again. Whereas most lymphoma research in this area has focused on vaccination strategies using the tumor-specific idiotype as a target antigen, this review focuses on the potential of a new strategy of adoptive transfer of antigen-specific T- for B-cell malignancies. Murine in vivo models and preclinical experiments suggest that we are now ready to enter the clinical arena to evaluate whether adoptive transfer of autologous or allogeneic antigen-specific T cells is a feasible and efficacious therapy approach for the treatment of B-cell malignancies. Potential obstacles to this strategy are also discussed.