National and regional policy initiatives have been recently implemented in Spain to facilitate the energy transition of the Spanish islands. However, several major challenges remain, as described in this study. Based on an inventory of the current legislation and information gathered via surveys and interviews, the Clean energy for EU islands secretariat has brought together all relevant stakeholders in two Focus Group meetings and a National Stakeholder Meeting to identify barriers to the clean energy transition on Spanish islands, and formulated recommendations to overcome them. These barriers relate to grid constraints, inflexible thermal power plants, lack of legal frameworks for renewable system integration, complex and lengthy permitting and authorisation procedures, spatial planning issues and need for improvement of coordination of energy sector priorities between the national and regional governments. The good news is that they can be overcome by constructive collaboration between the relevant actors. Regular dialogues and interactions between the island stakeholders and the stakeholders at national level will allow for improved national strategic and long-term energy planning and funding distribution.