Prevalence of erectile dysfunction (ED) has a higher incidence in patients treated for diabetes mellitus as it concerns more than 30% of them. ED's physiopathology is complex and multifactorial, involving a combination of classical risk factors (endothelial dysfunction), specific factors (e.g., diabetic neuropathy) and psychological factors. ED is most often forewarning a cardiovascular disease. Therefore, it needs to be detected by the physician who is taking care of the diabetic patient. ED is responsible for a deterioration of the quality of life. Therapeutic management relies, on one hand, on specific measures such as prevention of diabetic complications and, on the other hand, on psychological accompaniment of the patient. Phosphodiesterase-5 inhibitors have become the first-line treatment as they are efficient and safe in most cases. As a second line, intracavernous injections remain a gold-standard treatment but the vacuum can be proposed as well. In case of failure, penile prosthesis can even be considered. The psychological dimension of ED has to be considered as much as organic matters.