The central function of the liver in the regulation of the metabolisms of hormones and nutrients makes it an integral part of the endocrine system. In everyday clinical practice, the endocrinologist usually encounters patients with altered liver function tests. This condition might be a cause or a consequence of the endocrine disease (e.g. type 2 diabetes mellitus, polycystic ovary syndrome), an associated condition as in the case of concomitant autoimmune diseases, a consequence of a specific pharmacological treatment, or an unrelated condition. In this chapter, we focus on the most common causes of alteration of liver function tests and provide indications on how to perform the first assessment of liver disease and when to refer patients to a hepatologist.