Ejaculation is a synchronized cascade of events that has the ultimate goal of activating sperm and enabling them to reach an egg for fertilization. The seminal plasma contains a complex mixture of fluids that is secreted from the testes, epididymis and male accessory glands. The prostate gland has a pivotal role in this process, as prostatic fluid enriched in Zn(2+), citrate and kallikreins is crucial for the molecular synchronization of the functional cascade triggered by ejaculatory stimuli. The prostate is the target of a number of common diseases that can affect male fertility at different ages. In both young and aged men, prostatic diseases or an unhealthy prostate can affect spermatozoa functioning and, therefore, male fertility. Consideration of prostate physiology emphasizes a number of points: the central role of Zn(2+) and citrate in the regulation of prostate epithelium homeostasis and in ejaculation; the influence of bacteria-related prostatic inflammation on male fertility; and the potential role of prostatic inflammation in promoting the development of prostatic hyperplastic growth and carcinogenesis.