Mantle cell lymphoma is a B cell lymphoproliferative disorder cytogenetically characterized by the t(11;14)(q13;q32) which at molecular level involves the Bcl-1/PRAD-1 gene. Immunophenotypically it is characterized by co-expression of CD5+/CD20+ and CD23- antigens. Histologic patterns are recognized as: diffuse, mantle zone and nodular. Diffuse mantle lymphoma is the most frequent and is associated with a poor prognosis. The rearrangement of the Bcl-1/PRAD-1 increases the synthesis of cyclin D1. Cyclin D1 binds to Cdk4 and forms a complex, then binds to and phosphorylates Rb protein thus triggering cells to progress from G0/G1 to S and thus drives cellular proliferation. The 5-year survival in the MD Anderson series was less than 30% and anthracycline regimens do not appear to have any major impact on the outcomes of cases with nodular or diffuse histopathological patterns. Intensive therapeutic programs and first line autologous or allogeneic bone marrow transplantation remains experimental.