A recent article published in Advances in Experimental Medicine and Biology reported that lower levels of testosterone (T) in men with type-2 diabetes mellitus (T2DM) has been recognized for over two decades. It was stated that hypogonadism has been found in approximately 50% of men with T2DM with massive correlations with measures of obesity, such as waist circumference and body mass index (BMI). The article further discussed that in longitudinal studies, hypogonadism has been identified as a predictor of incident T2DM. While experimental withdrawal of T led to acute decreased insulin sensitivity, which could be reversed by normalization of T concentrations. On the other hand, androgen deprivation therapy, commonly used in men with advanced prostate cancer, significantly heightened the risk of incident T2DM. Although short-term studies of T therapy in hypogonadal men with T2DM exhibited minor effects, long-term administration of T led to meaningful and sustained improvements of glycemic control with parallel reductions in body weight and waist circumference. The more insulin-resistant and obese a patient was at the time of initiation of T therapy, the more improvements were noted. It was concluded that the observed effects are likely mediated by the increase in lean body mass invariably achieved by T therapy, as well as the improvement in energy and motivation, referred to as the psychotropic effects of T. It was proposed that measuring T levels and, if indicated, restoring mens T levels into the normal physiological range can have a substantial impact on ameliorating T2DM in hypogonadal men.