On behalf of the Organizing Committee, it is our great pleasure to welcome you to Seville and to the VII European Congress of Protistology (VII ECOP), hosted by the Specialized Group of Protistology (Grupo Especializado de Protistología, GEP) of the Spanish Society of Microbiology. The European Congresses of Protistology (ECOP) are the most visible activities of the Federation of European Protistological Societies (FEPS), a nonprofit association of 12 national and cross-national protistological societies in Europe. The VII ECOP congress will be organized for the first time as a joint meeting in partnership with the International Society of Protistologists (ISOP), a global society which has members across the world with interests in all areas of Protistology, and some of its affiliated societies are also constituent societies of FEPS. This will be a very special occasion, so we cordially invite you to actively participate in this outstanding meeting point for protistologists worldwide. The Congress has been designed to provide a comprehensive overview of the latest research developments in different protistological fields, from the molecular to the ecological ones. Contributions will be presented in the form of 8 plenary lectures, 12 symposia, a number of workshops and posters. These assure that the meeting will be a major scientific event. We are especially grateful to ISOP which organized and generously supported two symposia and two plenary lectures, one of them being the 2015 Hutner Award lecture. Therefore, the 2015 ISOP Meeting will take place in close connection with VII ECOP, one could say in a symbiotic-like way. The meeting will be held in two venues located near the centre of the city and at a walking distance from each other, the Hotel-Conference Center Sylken Al-Andalus Palace and the “Reina Mercedes” Scientific Campus of the University of Seville. We would like to deeply express our thanks to the University of Seville for its generous support, to I3 Congresos y Eventos for the excellent arrangement of logistical and technical aspects of the Congress, and to our dedicated staff, colleagues, friends and families for their untiring help, support and advice in planning and arranging this meeting. We hope that you will enjoy the Congress and that your interaction with your colleagues from different countries will stimulate a creative exchange of ideas and will be personally rewarding. We also hope and trust that you will enjoy your visit to the charming and beautiful Seville, an ancient historical city that for almost three centuries was the gateway to the Americas and a unique space for cultural and commercial exchange between Europe and the New World.