According to the epidemiologic studies conducted so far, premature ejaculation (PE) is the most common male sexual dysfunction in younger men (<30 years);its prevalence is higher than that of ED, and varies from 9% and up to 31% of the male population.The etiology of PE is uncertain in almost all cases, and might include a combination of organic and psychogenic factors.Negative conditioning and penile hypersensitivity are the most frequendy cited etiological factors in PE, although neither mechanism has received adequate experimental support to date.Accordingly from a scientific perspective, it is fair to state that PE pathophysiology is largely unknown.