Prostate cancer (PCa) is the second most common malignancy among men and the fifth leading cause of cancer-related mortality worldwide. In this study, a review of the literature was conducted in an attempt to clarify the relationship between green tea catechins (GTCs) and PCa. Published articles were searched using PubMed, Web of Science, Google Scholar, and Scopus databases. The study analysed the studies, which were mainly conducted between 2016 and 2025. Polyphenolic compounds are attracting increasing attention for their potential roles in cancer prevention and treatment, and many in vitro, animal, and clinical studies have explored the roles of polyphenols in cancer. Epigallocatechin gallate (EGCG), the predominant flavanol in green tea (GT), exerts significant therapeutic potential by inhibiting cell cycle progression, modulating oncogenic signalling, and interacting with nuclear transcription factors. These mechanisms suggest that EGCG may aid in PCa prevention and management, with evidence indicating that EGCG suppresses PCa cell proliferation by regulating androgen receptor activity and inducing apoptosis, potentially inhibiting tumour growth and metastasis. However, conclusive evidence supporting the use of EGCG as a therapeutic agent for PCa is still lacking. As detailed in this review, preclinical studies have demonstrated this compound’s promising anticancer activity, but clinical evidence on the effects of GTCs remains limited due to the small number of human trials and low sample sizes of studies conducted to date, as well as variability in GT formulations.