Some studies observed an association between erectile dysfunction (ED) and coronary artery disease (CAD) extent in the general population, but others did not. There are no specific studies in diabetic populations. The aim of the present study was to evaluate whether ED is correlated with the extent of angiographic CAD in a large group of type II diabetic patients. We recruited 198 consecutive type II diabetic males undergoing an elective coronary angiography to evaluate chest pain or suspected CAD. Presence and degree of ED were assessed by the International Index Erectile Function - 5 (IIEF-5) questionnaire. ED was considered present, when IIEF-5 score was ≤21. Moreover, each domain of IIEF-5 was considered. Angiographic CAD extent was expressed both by the number of vessels diseased and by the Gensini scoring system. The percentage of subjects with ED was significantly higher (45.8 versus 15.8%; P = 0.0120) in patients with (n = 179) than in those without (n = 19) significant angiographic CAD (stenosis of the lumen ≥50%). No significant association of CAD extent with presence of ED, total IIEF-5 score and each domain of IIEF-5 was observed. Our study shows that ED was significantly more prevalent in type II diabetic males with angiographic CAD than in those with normal arteries. However, no correlation was found between the extent of angiographic CAD and the presence or the severity of ED.