Erectile dysfunction (ED) is a common medical disorder affecting elderly men. Sildenafil citrate has been shown to be an effective and well-tolerated oral agent for treating ED in the general population of adult men with ED of broad-spectrum etiology. Elderly men are more likely to have concomitant medical problems than the general population of men with ED. In this study, we examined the efficacy and safety of sildenafil administration in elderly patients with ED. Forty-four elderly men with ED (> or = 60 years old) of broad-spectrum etiology were treated with 25 mg or 50 mg doses of sildenafil citrate. Age ranged from 60 to 78 years (65 +/- 4.5; means +/- S.D.). Mean follow-up period was 12.3 +/- 6.5 months, with a range of 1 to 25 months. Primary efficacy assessments were performed using the International Index of Erectile Function 5 (IIEF5) before their first dose of sildenafil and after at least 4 weeks of therapy. Serum testosterone was measured before treatment. The mean IIEF5 among all patients increased from 8.5 +/- 3.9 to 20 +/- 4.2 after sildenafil use (P < 0.0001). In patients younger than 70 years, the IIEF5 score increased from 9.5 +/- 5.0 to 17 +/- 4.3 while in patients 70 years and older, the score increased from 8.2 +/- 3.6 to 21 +/- 3.9, a near normalization. The rate of improvement in younger men was higher than in older men. Serum testosterone before treatment was similar in the two groups. The most commonly experienced adverse events were flushing and dyspepsia, which occurred in 6.8% and 2.3%, respectively. No patients discontinued sildenafil treatment due to adverse events. In conclusion, oral sildenafil is efficacious and well tolerated by elderly men with ED, even among those older than 70 years.