Hypogonadism is a syndrome characterized by low concentrations of serum testosterone and symptoms of testosterone deficiency, particularly low libido and sexual dysfunction. There are currently numerous safe and effective methods of testosterone replacement available for the treatment of hypogonadism. This chapter reviews the clinical benefits and potential side effects of treatment of currently available testosterone formulations and discuss the advantages and disadvantages of each formulation. In addition, we will review recommended patient monitoring during treatment and pharmacological alternatives to the use of testosterone for the treatment of hypogonadism in men.