Sexual dysfunction is frequent in the diabetic population. In Africa, medical care for erectile dysfunction is underprovided, profoundly altering the quality of life of the patients. We report the prevalence of erectile dysfunction in 187 diabetic patients followed in the department of Endocrinology of the Conakry teaching hospital. Prevalence was estimated from the French version of the International Index of Erectile Function (IIEF). Erectile dysfunction concerned 90 patients (48%) of whom a severe form was observed in 54%, a moderate form in 35% and a mild form in 12%. The patients who presented erectile dysfunction were significantly older, displayed longer duration of diabetes with more complications (sensorial neuropathy and macroangiopathy) and often took drugs for associated cardiovascular diseases. In 28% of the cases, erectile dysfunction was associated with a decline in libido and in 26% with ejaculation disorders. In conclusion, erectile dysfunction is frequent and severe among diabetic patients in Guinea. The medical staff plays an essential role to initiate early diagnosis, promote psychological support and provide medication, if possible.