The combination of rituximab (monoclonal antibody) and bendamustine (chemotherapy) has shown encouraging activity in patients with relapsed/refractory NHL or mantle cell lymphoma. In vitro studies have been used to investigate the effects of bendamustine and rituximab on programmed cell death (apoptosis) and have shown synergistic effects of both drugs. The mechanisms of action of these two active drugs may provide a treatment with good therapeutic potential in CLL. However, though bendamustine has been used for over 30 years there is still a need to define a standard regimen for the use of bendamustine in combination with monoclonal antibodies (mAb) especially in the treatment of CLL.