Patients with refractory angina often suffer from erectile dysfunction. Enhanced external counterpulsation (EECP) decreases symptoms of angina, and increases nitric oxide release. This study evaluated the effect of EECP on sexual function in men with severe angina. The International Index of Erectile Function (IIEF) was used to assess erectile function of severe angina patients enroled in the International EECP Patient Registry. Their symptom status, medication use, adverse clinical events and quality of life were also recorded before and after completing a course of EECP. A cohort of 120 men (mean age 65.0+/-9.7) was enroled. The men had severe coronary disease with 69% having a prior myocardial infarction, 90% prior coronary artery bypass graft or percutaneous coronary intervention, 49% with three vessel coronary artery disease, 86% were not candidates for further revascularisation, 71% hypertensive, 83% dyslipidaemia, 42% diabetes mellitus, 75% smoking and 68% using nitrates. Functional status was low with a mean Duke Activity Status Inventory score of 16.6+/-14.8. After 35 h of EECP anginal status improved in 89%, and functional status in 63%. A comparison of the IIEF scores pre- and post-EECP therapy demonstrated a significant improvement in erectile function from 10.0+/-1.0 to 11.8+/-1.0 (p=0.003), intercourse satisfaction (4.2+/-0.5 to 5.0+/-0.5, p=0.009) and overall satisfaction (4.7+/-0.3 to 5.3+/-0.3, p=0.001). However, there were no significant changes in orgasmic function (4.2+/-0.4 to 4.6+/-0.4, p=0.19) or sexual desire (5.3+/-0.2 to 5.5+/-0.2). The findings suggest that EECP therapy is associated with improvement in erectile function in men with refractory angina.