Although modern biotechnology has provided us with a greater understanding of the molecular events in endocrine-related diseases, such as benign prostatic hyperplasia and prostate cancer, these conditions continue to be a significant healthcare problem world-wide. As the number of men afflicted by these diseases will only continue to grow with the aging population, finding new strategies and new therapeutic options for the treatment of both of these diseases is crucial. A better knowledge of the mechanisms of hormone action is pivotal to making progress in the development of new hormone-based therapies. This is fundamental to increasing our understanding of the endocrine, paracrine, and autocrine signaling mechanisms in the prostate and in prostate disease, distinguishing the effects and role of each, and identifying where and how this communication goes wrong.