Green coffee oil (GCO) is a potential natural product for application in health care products. In this study, the properties of GCO from spent coffee grains were evaluated aiming its application in sunscreens. GCO showed an intense synergistic effect in SPF value when it was associated with the synthetic sunscreen ethylhexylmethoxycinnamate, leading to an increase of 20% in SPF. Additionally, the antioxidant activity, the cytotoxicity and the sun protection factor (SPF) of GCO were determined. The results show no cytotoxic effect for skin and liver cells in vitro, even at high concentrations. The results suggest the use of GCO as a potential natural product for sunscreens formulations to improve the efficiency and protection against skin damage. (C) 2013 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)