Serum markers can be important tools for prognostic classification and treatment monitoring in cancer patients. The MAP-kinase pathway, which is upregulated in the majority of melanoma patients, can be activated by hepatocyte-growth factor (HGF) through the proto-oncogene c-MET. The aim of this study was to evaluate the predictive and prognostic value of circulating HGF in terms of treatment outcome and survival compared with a widely established serum marker, protein S-100B, in patients with advanced metastatic melanoma. HGF and S-100B were measured in serum samples of 101 patients with metastatic melanoma (American Joint Committee on Cancer stage IV) before and after treatment and 50 patients with stage I/II melanoma. HGF and S-100B correlated significantly with the stage of disease (P=0.032 and P<0.001, respectively). In stage IV melanoma patients, baseline serum levels of HGF and S-100B were significantly associated with treatment response (P=0.012 and 0.006, respectively). Furthermore, the Cox regression analysis confirmed that serum levels of HGF and S-100B proved to have a significant prognostic impact on progression-free survival (hazard ratio=1.39 and 1.29, respectively) and overall survival (hazard ratio=1.27 and 1.29, respectively) in advanced metastatic melanoma patients. In melanoma patients, serum levels of HGF and S-100B correlate significantly with the stage of disease. In stage IV melanoma, both markers are prognostic factors and correlate significantly with progression-free survival and overall survival. Measurement of serum HGF levels might be a useful additional tool in the management of melanoma patients.