This article reports the development of oil-in-water nanoemulsions containing additives capable of dispersing asphaltenes and evaluation of their use as a new alternative for breaking down oil emulsions. The nanoemulsions were prepared in the presence of a surfactant based on polyethylene oxide using a high pressure homogenizer with different processing conditions, which led to different droplet sizes. These sizes influenced the stability and demulsification efficiency. All nanoemulsions were efficient in phase separation of water-in-oil emulsions. The nanoemulsion containing the additive was the one that promoted fastest separation. (C) 2016 Elsevier Ltd. All rights reserved.