Testosterone deficiency syndrome, which has sometimes been termed age-related or late-onset hypogonadism, is a syndrome characterized by both clinical manifestations as well as a biochemical deficiency of testosterone. This condition is associated with considerable morbidity and mortality, accounting for billions of dollars in health care costs. There is some evidence that suggests that restoring testosterone levels in these individuals may help to manage or delay progression of the associated morbidities. Furthermore, despite controversies in the literature and media, testosterone replacement has proven to be quite safe in most men with minimal if any adverse effects when dosing to achieve the eugonadal range. It is nevertheless very important for clinicians to be aware of the possible risks and contraindications of treatment to ensure proper patient selection and appropriate monitoring.