Angiogenesis plays an important role in progression of tumor with vascular endothelial growth factor (VEGF) being key proangiogenic factor. It was intended to study angiogenesis in different hematological malignancies by quantifying expression of VEGF and MVD in bone marrow biopsy along with serum VEGF levels and observing its change following therapy. The study included 50 cases of hematological malignancies which were followed for one month after initial therapy along with 30 controls. All of them were subjected to immunostaining by anti-VEGF and factor VIII antibodies on bone marrow biopsy along with the measurement of serum VEGF levels. Significantly higher pretreatment VEGF scores, serum VEGF levels, and MVD were observed in cases as compared to controls (p < 0.05). The highest VEGF score and serum VEGF were observed in chronic myeloid leukemia and maximum MVD in Non-Hodgkin's Lymphoma. Significant decrease in serum VEGF levels after treatment was observed in all hematological malignancies except for AML. To conclude angiogenesis plays an important role in pathogenesis of all the hematological malignancies as reflected by increased VEGF expression and MVD in bone marrow biopsy along with increased serum VEGF level. The decrease in serum VEGF level after therapy further supports this view and also lays the importance of anti angiogenic therapy.