Rituximab is a monoclonal antibody with proven efficacy in WM but responses are slow. Bortezomib has shown significant and rapid activity in WM. Combinations of bortezomib with rituximab nad dexamethasone with rituximab have shown synergistic activity in laboratory studies and clinical trials. This is a Phase II multicenter study designed to evaluate the safety and efficacy of the combination of Bortezomib , Rituximab and dexamethasone (BDR). BDR will be administered in one 21-day treatment cycle followed by four 35-day treatment cycles to patients with WM. Bortezomib will be administered as an iv push over 3 to 5 seconds at a dose of 1.3mg/m2/day on days 1,4,8 and 11 of cycle 1. On cycles 2-5 bortezomib will be given at a dose of 1.6mg/m2/day on days 1,8,15 and 22 of each cycle. Only on cycles 2 and 5, following the administration of Bortezomib, dexamethasone 40mg iv and Rituximab 375 mg/m2 iv will be administered. A total of 8 infusions of rituximab will be administered. Subsequently patients rated as CR, PR, MR or SD will be followed without any treatment until there is evidence of progressive disease.