This book constitutes the refereed proceedings of the International Conference on Geographical Information Systems Theory, Applications and Management, held in Barcelona, Spain, in April 2015. The 10 revised full papers presented were carefully reviewed and selected from 45 submissions. The papers address new challenges in geo-spatial data sensing, observation, representation, processing, visualization, sharing and managing. They concern information and communications technology (ICT) as well as management of information and knowledge-based systems.