Simple Summary: Prostate cancer (PCa) is a serious men's health problem worldwide. Some authors report the occurrence of the Epstein–Barr virus (EBV), a well-known oncovirus, in PCa. Therefore, in this study, PCa tissues were screened for the presence of EBV. Then, the frequency and titer of antibodies against EBV in the serum of EBV-positive and EBV-negative patients were compared. The results obtained showed a higher frequency and level of Epstein–Barr virus capsid antigen (EBVCA) and Epstein–Barr nuclear antigen 1 (EBNA1) antibodies in patients with EBV-positive PCa. Higher levels of tested antibodies were observed in more advanced stages of the disease (high-risk group, high Gleason score (GS) and stage T2). These observations may suggest a role for EBV in the development and/or progression of PCa. Prostate cancer (PCa) is the fourth most frequently diagnosed cancer worldwide, accounting for 7.3% of all cancers. PCa mortality is the fifth most common cause of cancer death. Despite well-known factors influencing the development of PCa, such as age, race/ethnicity and family history, many researchers have raised the possibility of persistent infections with oncogenic viruses. Therefore, we aimed to assess the frequency of Epstein–Barr virus (EBV) DNA in tissue collected from PCa patients. Next, the frequency and the level of Epstein–Barr virus capsid antigen (EBVCA) and Epstein–Barr nuclear antigen 1 (EBNA1) antibodies in both IgA and IgG classes were measured. The antibody titer was also analyzed depending on the risk group, Gleason score (GS) and tumor, node, metastasis (TNM) classification. Serum samples were analyzed using the Microblot-Array EBV IgM, IgA and IgG test kits. The study group consisted of 115 patients diagnosed and histopathologically confirmed with PCa. In 49% of patients included in the study, EBV DNA was detected in the tumor tissue. The studies showed both higher seroprevalence and higher antibody titers in patients with EBV-positive PCa compared to patients with EBV-negative PCa. We also observed a dependence of antibody titer on pathological features, such as GS, risk group and T stage. [ABSTRACT FROM AUTHOR]