The relationship between prostatic chronic inflammation (PCI) and prostate cancer (PCa) is unclear and controversial. Some authors reported that a history of chronic prostatitis may be correlated with PCa induction, while others associate chronic inflammation with less aggressive disease or consider inflammation as a possible protective factor against PCa. Four different types of prostatitis are known: bacterial acute prostatic inflammation, bacterial chronic prostatic inflammation, abacterial prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatic chronic inflammation. Prostatic inflammation is underestimated during daily clinical practice, and its presence and degree often go unmentioned in the pathology report of prostate biopsies. The goal of this report is to further our understanding of how PCI influences the biology of PCa. We investigated the main pathogenetic mechanisms responsible for prostatic inflammation, including the cellular response and inflammatory mediators to describe how inflammation modifies the prostatic environment and can lead to benign or malignant prostatic diseases. We found that prostatic inflammation might have a pivotal role in the pathogenesis of prostatic diseases. Details about PCI in all prostate biopsy reports should be mandatory. This will help us better understand the prostatic microenvironment pathways involved in PCa biology, and it will allow the development of specific risk stratification and a patient-tailored therapeutic approach to prostatic diseases.