BackgroundMen with erectile dysfunction often have concurrent medical conditions. Conversely, men with these conditions may also have underlying erectile dysfunction. The prevalence of unrecognized erectile dysfunction in men with comorbidities commonly associated with erectile dysfunction was determined in men invited to participate in a double-blind, randomized, placebo-controlled trial of sildenafil citrate.MethodsMen ≥30 years old presenting with ≥1 erectile dysfunction risk factor (controlled hypertension, hypercholesterolemia, smoking, metabolic syndrome, stable coronary artery disease, diabetes, depression, lower urinary tract symptoms, obesity [body mass index ≥30 kg/m2] or waist circumference ≥40 inches), and not previously diagnosed with erectile dysfunction were evaluated. The screening question, "Do you have erectile dysfunction?," with responses of "no," "yes," and "unsure," and the Erectile Function domain of the International Index of Erectile Function (IIEF-EF) were administered.ResultsOf 1084 men screened, 1053 answered the screening question and also had IIEF-EF scores. IIEF-EF scores indicating erectile dysfunction occurred in 71% (744/1053), of whom 54% (399/744) had moderate or severe erectile dysfunction. Of 139 answering "yes," 526 answering "unsure," and 388 answering "no," 96%, 90%, and 36%, respectively, had some degree of erectile dysfunction. The mean±SD (range) number of risk factors was 2.9 ± 1.7 (3-8) in the "yes" group, 3.2 ± 1.7 (3-9) in the "unsure" group, and 2.6 ± 1.5 (2-8) in the "no" group.ConclusionAlthough awareness of having erectile dysfunction was low, most men with risk factors had IIEF-EF scores indicating erectile dysfunction. Erectile dysfunction should be suspected and assessed in men with risk factors, regardless of their apparent level of awareness of erectile dysfunction.Trial registrationClinicalTrials.gov Identifier NCT00343200.