Prostate cancer is a disease that is greatly affected by lifestyle, particularly diet, and is more prevalent in US and European countries compared with South and East Asia. Among several known causes and risk factors, nutrition plays an important role in prostate cancer pathogenesis. Various dietary components including polyphenols have been shown to possess anticancer properties. Dietary polyphenols have been the subject of extensive studies for the last decade because of their anticancer and chemopreventive potentials. Besides possessing various antitumor properties, dietary polyphenols also contribute to epigenetic changes associated with the fate of cancer cells and have emerged as potential drugs for therapeutic intervention. Various polyphenols have been shown to affect DNA methylation, histone posttranslational modifications, and microRNA expression patterns in prostate cancer. In this review, we discuss the contribution of dietary polyphenols to various epigenetic modifications in prostate cancer. Since prostate cancer and diet are intimately associated, polyphenol-rich diets that epigenetically modify tumor biology have great significance in the prevention and management of prostate cancer.