The availability of adequate treatment for erectile dysfunction (ED) triggers studies into the prevalence of ED in the general population. Yet, previous studies showed different prevalence estimates partly due to differences in patient selection, in (unclear) definitions of ED and in assessment. ENIGMA has been designed to study the prevalence of ED in the general population of The Netherlands, using the WHO definition with a description of the way of assessment. In all, 5721 mail surveys were sent to all men, aged 18 y and older in 12 general practices in The Netherlands. A total of 5601 were included in the study and 2117 (38%) were completed. A total of 38% of the men reported to have ever had some kind of erectile problem. The prevalence of ED was 17% (6% mild, 4% moderate and 7% complete). Age, diabetes, cardiovascular diseases, penile disorders, irradiation in the pelvic region, relational problems, fear for failure, surmenage, medication use and regular consumption of alcohol were independently related to ED. Men with ED were less content with their (sexual) life and had less confidence in sexual performance. Presence of ED was negatively related to affected happiness in life. ED is commonly found in men and is related to age, medication, comorbidity and lifestyle factors. Men with ED perceive a lower quality of (sex)life. Doctors should be aware of the presence of ED and its consequences in patients.