Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid malignancies. The treatment strategy for patients with NHL had remained unchanged until the advent of the era of molecular targeting agents. Although rituximab-containing chemotherapy has improved the response rates and survival of patients with B-cell NHL (B-NHL), several subtypes of B-NHL, especially indolent B-NHL and mantle cell lymphoma (MCL), remain incurable. Therefore, novel treatment modalities for B-NHL, especially for indolent B-NHL and MCL, are needed. Bendamustine is an old, but unique, multifunctional cytotoxic agent that exhibits structural similarity to alkylating agents and purine analogs. Areas covered: The basic aspects and preclinical development of bendamustine are summarized, followed by a discussion of the clinical development of bendamustine-based treatments for indolent B-NHL and MCL. Expert opinion: Bendamustine monotherapy or the use of bendamustine in combination with rituximab is highly effective against various types of hematological malignancies, especially relapsed or refractory indolent B-NHL, and exhibits an acceptable toxicity profile. Furthermore, bendamustine plus rituximab might be a promising treatment option for patients with untreated indolent B-NHL. Therefore, bendamustine has the potential to play an important role in the treatment of malignant lymphoma.