We evaluated microvessel density (MVD) in bone marrow biopsies (BM) from multiple myeloma (MM) patients after staining with anti-CD34 and anti-CD105 antibodies (mAbs). The anti-CD105 mAb was significantly more sensitive than the anti-CD34 mAb in visualizing blood vessels both in controls and MM samples. MVD was significantly higher in MM than in controls with both anti-CD34 and anti-CD105 mAbs. Patients with low CD34+ MVD survived longer than patients with higher MVD (P = 0.01), whereas there was no difference in survival between patients with low and high CD105+ MVD. Multivariate analysis confirmed the independent significant association between CD34+ MVD and survival (P = 0.001).