Intravascular large B cell lymphoma (IVLBCL) is a rare variant of diffuse large B cell lymphoma. We reported the clinical and immunohistochemical characteristics of 10 cases of IVLBCL from Taiwan between 1995 and 2008. Methods: Clinical data were reviewed and immunoperoxidase stains were performed with antibodies against CD20, CD10, Bcl-6, MUM1, and CD5. Results: There were eight males and two females with a median age of 59 years. Patients presented with dyspnea (5/10), fever (7/10), splenomegaly (5/10), and bone marrow involvement (8/10). Anemia (9/10), thrombocytopenia (6/10), and elevated serum lactate dehydrogenase or ferritin levels (8/10) were also common. Nine cases were CD20+CD10−Bcl-6−, similar to non-germinal center B cells. Six out of seven patients survived after chemotherapy, but three cases with thrombocytopenia that precluded chemotherapy died within 2 months. Conclusion: Our cases of IVLBCL had a non-germinal center B origin and belonged to the Asian variant of this disease. The liver, spleen, and bone marrow, but rarely the skin or brain, were involved. Thrombocytopenia is a major risk factor for mortality in these cases.