Obesity and a lack of sufficient physical activity (PA) are recognized as risk factors for most civilization diseases, including cancer. This study synthesized the current evidence evaluating the relationship between excess body weight and prostate cancer (PCa) in the relation to the disease risk, progression, and mortality, and identifies biological plausibility of the association. We also estimated the importance of PA in intentional body weight loss. Several electronic major databases to identify eligible articles were searched until March 2022. A total 22 observational articles, the literature on the underlying biological mechanisms, and the crucial evidence of a role of PA in body weight maintenance and reduction were reviewed. the available knowledge suggests that association between body mass index and PCa is conflicting. however, the most research consistently shown that overweight/obesity was associated with higher risk of high-grade PCa and dying of PCa. overweight/obesity can promote high-grade Pca through increased levels of secreted adipokines, increased formation of proinflammatory agents, and reduced concentration of adiponectin, among others. Being obese may by also linked with a higher risk of mortality. Exercise can decrease these health consequences related with obesity and may be effective in reduction of PCa-specific mortality, however, there are relative few studies on PA and PCa prevention among obese individuals.