This study compared demographic characteristics and prevalence of cardiovascular comorbidities between men with mild erectile dysfunction (ED) and men with more severe ED. Men with 6-month history of ED and in monogamous heterosexual relationships were included. Non-responders to type 5 phosphodiesterase inhibitors or patients receiving regular treatment with nitrate, anticoagulants, androgens, and anti-androgens were excluded. ED was defined according to the International Index of Erectile Function questionnaire score: no ED (≥26), mild ED (22-25), and others (<22). The review identified 70 patients with mild ED (6.0%, group A) and 1098 patients with more severe ED (94.0%, group B) were included. Of the patients in group B, 365 had mild-to-moderate ED (30.5%), 505 had moderate ED (43.2%), and 233 had severe ED (20.0%). Mean ages and body mass indices showed no differences between groups A and B. Group A had shorter mean duration of ED (p = 0.025). Although patients in group A had milder ED with shorter duration than group B patients, cardiovascular risk factors such as diabetes, hypertension and lipid disorder were still common for group A. The most common comorbidity was diabetes, which was twice as likely for patients in group B. Except for diabetes the prevalence of all diseases was comparable between the two groups. In conclusion, patients with mild ED should be closely evaluated for cardiovascular comorbidities.