Background: High levels of vascular endothelial growth factor (VFGF) have been reported in patients with cancers of different origins. There are no data comparing serum VEGF levels of medullary thyroid carcinoma (MTC) patients with that of the healthy subjects. Objective: We tried to assess whether serum VEGF concentration in MTC patients is correlated with tumour extension and whether this marker might be used to further refine the selection of candidates for future therapies with receptor tyrosine kinase inhibitors. Methods: Sera front 57 individuals divided into five groups: group I. healthy individuals (n = 14): group II. MTC patients in remission (n = 10): group III. MTC patients with residual disease (n=12): group IV. MTC patients with loco-regional disease (n =11) and group V, MTC patients with distant metastases (n=10) were analysed for serum VEGF and calcitonin (CT) levels. Results: Analysis of serum VEGF did not disclose significant differences among the five groups. Mean serum VEGF level of patients with distant metastases was not significantly different from that observed in healthy individuals (319.4 +/- 49.78 vs.313.7 +/- 43.13 ng/l). Serum VEGF levels correlated positively with serum CT (r=0.4891; P=0.0394) for CT values below 2500 ng/l whereas there was no correlation for CT values above this threshold. Conclusions: Serum VEGF levels in MTC patients are not significantly different from those found ill healthy individuals and did not correlate with the extension of disease.