The aim of the study was to analyse the socio-demographic and epidemiological characteristics of the Italian male population affected by sexual disturbances. Men complaining of erectile dysfunction (ED) who called the Pfizer program "Man and Woman in Health" between April 18th 2001 and May 27th 2002 and asked for information about their medical condition, were interviewed by trained doctors using a computer-assisted questionnaire. 16007 out of 25018 calls were considered for statistical analysis. Mean age of callers was 48.8+/-14.2 yr, reporting ED in 83% of cases. In the majority of men ED was severe (58%) and lasting more than 3 yr (25%). Multivariate analysis revealed that diabetes, depression, prostate surgery, heart disease, neurological disorders, liver and renal diseases were all significant and independent contributors to the degree of erectile impairment adjusted for age (p<0.001). The principal concomitant medications were anti-hypertensive (23%), antidiabetic (9%) and cardiovascular agents (6%). Cigarette smoking was present in 24%. On directed questioning of the caller, anxiety and distress were perceived as the most frequent causes of ED (42%) across all age groups, followed by the presence of concomitant disease/s (26%) especially in aging men. Also, a large number of men (41 %) with severe ED waited for more than 3 yr before looking for medical referral. Interestingly, only 19% had ever tried any specific medication for ED. These data indicate that 5 yr after worldwide approval and release of sildenafil, ED is still largely undiagnosed and under-treated, possibly because it is still perceived as a condition mainly due to distress or advancing age and therefore not deserving medical referral. Effective prevention of ED commences with better awareness of the pathological causes by the population and modification of risk factors by the doctors.