Olive tree is a traditional plant which fruits (Olea europaea L.) are used for olive oil production, especially in Mediterranean countries. Olive oil extraction produces by-products, which can become a major environmental issue. Recently, some studies have been carried out on these residues regarding phytochemical identification and biological and toxicological evaluation. The bioactive compounds contained by these by-products have a high antioxidant activity (especially oleuropein), a characteristic fatty acids profile and an interesting mineral composition. Indeed, taking into account its composition and sustainability issues, the reuse of these disposal residues is advisable. These agro-industrial by-products have the potential to be used with different purposes, providing economical advantage. In particular, the field of skin care products and cosmetics may benefit from these remaining materials, as those bioactive compounds can fulfill a real cosmetic function and activity. This review presents the composition of the different olive by-products and their bioactive compounds. The possible application of these wastes as cosmetic ingredients was critically reviewed. (C) 2015 Elsevier B.V. All rights reserved.