Recent investigations support the idea that angiogenesis is involved in the pathophysiology of hematologic malignancies, including chronic myeloid leukemia (CML). The aim of the present study was to evaluate plasma levels of VEGF and bFGF in a cohort of 51 chronic-phase CML patients at the time of diagnosis, as well as to investigate the effect of imatinib therapy on VEGF amounts in CML patients. Plasma VEGF levels were significantly higher in patients studied as compared with the 20 healthy subjects (p<0.001), the median plasma VEGF level detected in patients analysed and healthy controls was 433.4 pg mL(-1) (range 65.2-2,452.7 pg mL(-1)) and 81.6 pg mL(-1) (range 44.2-338.7 pg mL(-1)), respectively. On the other hand, no difference in bFGF plasma levels could be found between chronic-phase CML patients and the control group. There were significant associations between plasma VEGF levels and some characteristics of patients evaluated, with trends for higher VEGF values in patients with enlarged spleens (p = 0.02) and those with higher platelet count (p<0.001). Of the patients, 11 received imatinib treatment. The initial VEGF levels markedly decreased after 6 months of imatinib therapy in each patient (p<0.001). These data support the important pathophysiological role of VEGF in CML. Further studies aiming to explore the detailed angiogenic profile of CML may help in developing new therapeutic strategies for this myeloproliferative disorder.