This chapter explores the therapeutic and nutritional usage of sacha inchi nut oil and its applications in health and disease prevention. It was found that the oil contains remarkably high contents of α-linoleic acid and linolic acid. Sacha inchi oil is therefore classified as an edible oil with the highest proportion of unsaturated fatty acids. As the oil also has a high content of γ- and δ-tocopherols, it is, despite its high proportion of unsaturated fatty acids, comparably stable against oxidation. Furthermore, vitamins A and E, and phytosterols, mainly stigmasterol, campesterol, and {increment}5-avenasterol have also been identified. Medicinal applications of the seeds and the oil have been discussed for a variety of diseases. Besides their cholesterol- and blood-pressure-lowering properties, it is also presumed that health improvements can be obtained in diabetes, arthritis, and even in the case of certain psychological disorders and cancers. Due to its high contents of omega-3, omega-6, and omega-9 fatty acids, the oil is used in medical and cosmetic applications. Despite relatively high tocopherol concentrations, the oil is comparatively stable against oxidation. Prospective fields of application are coronary heart disease, arthritis, diabetes, ADHD, and inflammatory skin diseases.