Lower urinary tract symptoms (LUTS) and sexual dysfunction are highly prevalent in aging men. Both conditions also are significant contributors to overall quality of life. New data have emerged to indicate potential links in epidemiological, physiologic, pathophysiologic, and treatment aspects of these two entities. There are numerous publications based on sophisticated community and clinical-based data, suggesting a strong and consistent association between LUTS and erectile dysfunction (ED). The association is supported by the consistent linear relationship of more severe LUTS with more severe ED. The link between ED and LUTS has biologic plausibility given the four leading theories of how these diseases inter-relate.