Erectile function (EF) is a complex process controlled by a variety of factors, including vascular, neurological, psychological and endocrinological function. There is a complex interrelationship between endocrine health and sexual function, particularly reflecting the importance of testosterone and the contribution of other hormones in EF and the association of hormonal imbalances in the occurrence of erectile dysfunction (ED). Indeed, while wide literature evidence corroborates a strong link between hypogonadism and ED, a consistent association between hyperprolactinemia and ED is highlighted by less numerous studies, and less abundant and consistent studies suggest an association between hypo- and hyperthyroidism, hypo- and hypercortisolism and growth hormone (GH) deficiency and excess on the one hand, and the occurrence of ED, on the other. Moreover, the endocrine system modulates EF also by means of its bidirectional relationship with metabolic health; in particular, metabolic syndrome represents a risk factor for hypogonadism, which in turn is associated with an increased prevalence of metabolic disorders and ED. Furthermore, metabolic syndrome directly increases the risk of ED through cardiovascular impairment and endothelial dysfunction. Evidence suggests that the presence of specific hormonal imbalances, such as in testosterone, prolactin and thyroid hormone levels, and of metabolic alterations in patients affected by ED may be of considerable clinical relevance. Accordingly, sexual function and EF should be assessed in patients with hormonal imbalances, particularly patients with hypogonadism and hyperprolactinemia, and with metabolic disorders.