Functional hypogonadism is a common disorder among patients with obesity and type 2 diabetes mellitus and could be managed by first treating the underlying causes. The present study was undertaken to investigate the contribution of body weight and glycemic control to the reversibility of hypogonadism to eugonadism in a real-life setting. Adult obese male patients with uncontrolled type 2 diabetes mellitus, complaining of mild to moderate erectile dysfunction and suspected of functional hypogonadism evaluated at our institution from 2015 to 2017, were retrospectively included. The gonadal status 3 and 12months after the glucose-lowering medication prescription was assessed. Seventy-one consecutive patients were enrolled, with 24 (34%) of them achieving total testosterone ≥300ng/dL (10.4nM/L) at the end of the study. When they were stratified according to HbA1c and body weight loss, a direct correlation was found for the latter only. Particularly, 94% of patients achieving a body weight loss >10% presented with total testosterone ≥300ng/dL. An inverse correlation was found for HbA1c, with no higher prevalence of total testosterone ≥300ng/dL in patients with HbA1c <6.5%. The findings are strengthened by the rigorous study design. However, a limited number of patients and glucose-lowering medications could be included. The present study supports the hypothesis that in obese patients with uncontrolled type 2 diabetes mellitus losing weight may have a greater impact on androgens compared to improving glycemic control. Further prospective studies are needed to corroborate this finding.