AbstractThe Pilot Project “SeaCleaner” is a citizen science and educational project, developed by the Institute of Marine Sciences of the Italian Research Council (CNR-ISMAR). Since 2013, it has involved environmental nongovernmental organizations (NGOs), volunteers, five Italian Marine Protected Areas surrounding the Pelagos Sanctuary, and so far more than 50 high school students within the Italian program for “work-related learning internships.” The project aims to overcome the lack of current data on marine litter—a gap of knowledge that cannot be ignored any longer, according to the last European Union's ambitious Marine Strategy Framework Directive (MSFD)—by building an app for Android devices, which is easy to use and, at the same time, methodologically sound and comprehensive. This should enable a continuous census (in time and space) for supporting the proper management and removal of solid waste (through scheduled campaigns, etc.). The project has multiple effects: (1) to prompt students to broaden their scientific knowledge on topics not strictly related to scholastic curricula, making them aware of current environmental problems and teaching them how to solve them; (2) to engage an increasing number of volunteers in marine litter monitoring activities; and (3) to contribute to a common protocol for data acquisition, useful for both environmental and scientific purposes, helping scientists to overcome the lack of current data on marine litter.