From the first week of July until the end of October 2018, three controlled groups of participants with mental illnesses, limited to 10 people in each group, were taken to a natural path (part of the pilgrims way Camino de Santiago) in the Biosphere Reserve of Urdaibai (Northern Spain) once a week for two hours with a trained forest bathing guide. These interventions are free of charge for all users. AVIFES is carrying out forest therapy users’ evaluation: physical measurements before and after each session (oxygen saturation, blood pressure and heart rate) are taken and, for the psychological purpose, they are using a quality of life model for people with intellectual disabilities, adapted by AVIFES for people with mental illnesses. This model analyses different factors that serve as indicators to evaluate quality of life. These factors are analysed for each user after each intervention. Once the project is over, information boards will be installed and the site will become a public forest bathing location. Forest owners of the land where the path runs have received 500 € each for a three-month use of their land. All costs in the project were met by the Basque Country Government and EAFRD funds