The objective of this work is to determine the chemical stability of cosmetic argan oil (INCI: Argania spinosa kernel oil). The methodology involves the repeated measurement over a 1-year period of the quality metrics used in the cosmetic industry: acid and peroxide value and specific absorbance. During this year, storage is performed at 40° or 25°C to assess the importance of temperature. In this latter case, oil samples have been either protected or exposed to sunlight. In addition, sterol and fatty acid composition is determined to attest argan oil chemical integrity over 1 year. Storage of argan oil at 40°C results in a rapid loss of quality. Stored at 25°C and protected from sunlight, argan oil quality is still satisfactory after 12 months according to the official Moroccan norm, but storage should not be longer than 6 months to fulfill industrial standards.