Introduction: Testosterone levels are frequently low in men with type two diabetes mellitus, and sexual symptoms are a prominent presenting feature for these men. Objectives: The aim of this study was to determine the frequency of hypogonadism and related risk factors among Tunisian patients with type two diabetes mellitus and erectile dysfunction. Methods: This cross–sectional study included a total of one hundred and thirty consecutive men with type two diabetes and erectile dysfunction who attended the Internal Medicine and Endocrinology Department, Monastir University Hospital, Tunisia. Erectile function was assessed using the International Index of Erectile Function score (IIEF). All the patients submitted the fully completed Androgen Deficiency in Aging Male (ADAM) questionnaire. Hypogonadism was defined as total testosterone < twelve nmol/l. Results: Of the one hundred and thirty total patients, twenty one per cent exhibited decreased libido, and sixty–one per cent reported more than three symptoms of ADAM. Hypogonadism was present in forty one patients. Among these patients, hypogonadotropic hypogonadism was the most prevalent form (seventy per cent). Patients with hypogonadism had lower Index of Erectile Function score compared to those with normal total testosterone. Significant negative correlation was found between total testosterone and body mass index, waist circumference, androgen deficiency symptoms, and HBA1c. In logistic regression analysis, erectile dysfunction severity and HBA1c were statistically significant risk factors for hypogonadism. Conclusions: Considering that hypogonadism is frequent in type two diabetic subjects with erectile dysfunction, an appropriate screening should always be performed in those patients in order to detect those who have low serum total testosterone level at any early stage and to supplement testosterone -accordingly.