The present study investigated the significance of the serum brain-derived neurotrophic factor (BDNF) and platelets in relation to the clinicopathological features of hepatocellular carcinoma (HCC) patients. Localization of the BDNF expression in human HCC tissues was performed by immunohistochemistry. The measurement of soluble BDNF in the serum was performed by enzyme-linked immunosorbent assay. BDNF was expressed in the cytoplasm of the tumor cells. A positive correlation between the tissue and serum levels of BDNF was identified in the HCC patients. The serum levels of BDNF were positively correlated with the platelet counts in the HCC patients. A higher level of serum BDNF was significantly correlated with a tumor size >5 cm, poorly differentiated HCC, the presence of microsatellite tumor nodules, and the absence of cirrhosis in the non-tumorous tissues. A higher level of the serum BDNF/platelet ratio was associated with a poorer disease-free survival after hepatic resection. This study suggested that the tumor cell was a source of serum BDNF in HCC. A higher serum BDNF level was associated with a more advanced tumor status in the HCC patients. The interaction between serum BDNF and platelets might play an important role in HCC tumor progression.