Hepatitis C virus (HCV) is the main cause of chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC) worldwide. The risk to develop HCC increases with the severity of liver inflammation and fibrosis. Long pentraxin 3 (PTX3) is a soluble pattern-recognition receptor produced by phagocytes and nonimmune cells at sites of inflammation or injury. The aim of the present study was to determine the association of PTX3 polymorphisms and its plasma levels with HCC occurrence among patients with HCV. Samples from 524 patients with chronic hepatitis C were evaluated in this study. Two polymorphisms (rs1840680 and rs2305619) in the PTX3 gene were determined by real-time PCR. PTX3 plasma levels were measured by Enzyme-linked Immunosorbent Assay (ELISA). Our data show a significant association between PTX3 polymorphisms and HCC occurrence in univariate and multivariate analysis (P = 0.024). Patients with HCC had higher PTX3 plasma levels compared to individuals with mild or severe fibrosis (P < 0.0001 and P = 0.002, respectively). In addition, PTX3 rs2305619 polymorphism and plasma levels were correlated with Child-Pugh scores B and C in HCC individuals. PTX3 seems to be a risk factor for HCC occurrence in chronic hepatitis C. This is the first study that evaluates PTX3 in the context of hepatitis C.