Milk thistle is a herbaceous plant and is part of the characteristic vegetation of all those lands that overlook the Mediterranean Sea. The plant is known for its use as a herbal medicine. This medicinal plant is known for its beneficial properties for the treatment of liver disorders and other diseases. Such effects are related to its ability to act as free radical scavenger as well as to the activation of antioxidant enzymatic system (i.e. heme oxygenase-1). The aim of the present review is to provide a tool for the clinicians in order to exploit the beneficial effects of milk thistle expecially for those conditions in which the modern pharmacology has not yet developed a success-fult strategy of treatment (i.e. Nonalcoholic Liver Disease).