Non-Hodgkin's lymphomas (nHL) is a heterogenous group of lymphoid malignancies with different patterns of behaviour and response to treatment. International Prognostic Index (IPI) is commonly used to predict outcome of treatment in nHL. There are several reports that vascular endothelial growth factor (VEGF), the most potent inducer of angiogenesis, may have prognostic significance in nHL. The aim of the study was to evaluate the serum level of VEGF as a marker of angiogenesis in 35 patients with B-cell nHL compared with control group of 14 healthy people. Moreover, in nHL group VEGF serum level was correlated with IPI risk factors. VEGF serum level was evaluated by ChemiKine sandwich ELISA kit (Chemicon International). VEGF serum level was significantly higher in nHL group than in the control, 193.78 pg/ml +/- 6.82 SEM and 31.51 +/- 1.67 SEM respectively. In nHL group a positive correlation was found between increased VEGF serum level and serum lactate dehydrogenase level. The levels of VEGF were not significantly different in agressive or indolent nHL patients. VEGF serum level is increased in active lymphoma. This observation may have prognostic and clinical significance and provides rationale for use antiangiogenic agents in nHL therapy.