Lepidium meyenii, better known as maca, is a plant that grows 4000 m above sea level in the Central Andes. It has been used in Peruvian traditional medicine for centuries, with reports of its use to increase the offspring of domestic animals dating back from the 16th century. Traditional knowledge about its handling, preparation methods, and beneficial properties have survived until today, and guided the scientific community to conduct experimental trials to test the veracity behind these claims. The main health effects of maca as an energy booster and fertility enhancer herb has been confirmed in animal models and clinical trials. Other properties unknown to native Peruvians have also been discovered. This chapter aims to cover the tradition behind the medicinal usage of this nutritional plant and the scientific research that demonstrates its properties.