Waldenstrom's macroglobulinemia (WM) is a lymphoplasmacytic lymphoma characterized by the presence in patients' serum of an I-M monoclonal component. We report on our experience with 60 WM patients, focusing on their clinical findings, response to treatment, and the possible identification of prognostic factors. Of these patients, 70% presented with fatigue, and lymphadenopathy was observed in 22%, splenomegaly in 18%, hepatomegaly in 13%, and extranodal site of involvement in 6%. Bleeding tendency was seen in 17%, infections in 17%, hyperviscosity syndrome in 12%, and cardiac failure in 25% of the patients. The median of IgM levels was 30 g/l with hypoalbuminemia in 20% of cases, hypogammaglobulinemia in 27%, polyclonal hypergammaglobulinemia in 15%, kappa light-chain restriction in 78%, and Bence-Jones proteinuria in 54%. Anemia was frequent (85%), followed by leukocytosis (18%), lymphocytosis (12%), leukopenia (10%), and thrombocytopenia (10%). Cryoglobulinemia and autoimmune hemolytic anemia were encountered in 5%. In all cases but two, bone marrow was involved. Of 50 patients initially treated with intermittent oral chlorambucil, 46 (92%) responded. Median overall survival was 108 months. Factors associated with adverse prognosis were age greater than or equal to65 years (p=0.06), presence of lymphadenopathy (p=0.06), bone marrow infiltration greater than or equal to50% (p=0.007), international prognostic index (IPI) greater than or equal to3 (p=0.0001), and Morel's scoring system (p=0.04). Concluding, we found in this series of WM patients that chlorambucil is an effective treatment and that the parameters of age, lymphadenopathy, percentage of bone marrow infiltration, IPI, and Morel's scoring system carry prognostic significance.