Ethyl lactate is a very important environmentally friendly solvent which liquid phase structure, pure or water mixed, is determined by its ability to develop intra and intermolecular association through hydrogen bonding. In this work, the molecular level features that control its behaviour are analyzed using a wide collection of experimental tools. Results for pure ethyl lactate show strong intermolecular association competing with intramolecular hydrogen bonding. For water containing mixtures, the addition of small quantities of ethyl lactate to liquid water has a strong effect on liquid structure reinforcing the water networks whereas for ethyl lactate rich fluids the addition of water has less remarkable effects. (c) 2008 Elsevier B.V. All rights reserved.