Integrated Coastal Zone Management is widely recognised as a set of principles, approaches and tools for the sustainable development of coastal zones. However, while its importance as a theoretical framework for approaching the complexity of coastal governance is not opinable, the problem of translating ICZM principles into every-day management practice still represents a basic point to deal with. This paper aims at clarifying the most important elements that hinder ICZM adoption and implementation. To this purpose, it critically evaluates the results of the EU FP7 Project PEGASO (People for Ecosystem-based Governance in Assessing Sustainable development of Ocean and coast). The project considered ICZM efforts and initiatives in 10 case studies, 7 in the Mediterranean Sea and 3 in the Black Sea. The study confirms that dealing with the multi-scale nature of coastal governance, the poor coordination of policies and administrative fragmentation, the dictatorship of sectoral approaches, the difficulty to promote integration, both thematic and geographic, the complex relationship between voluntary agreements and statutory frameworks, the difficult relationship between science and decision making, and the problem of the sustainability over time of ICZM initiatives and efforts still represent the main factors that hamper a wider adoption of ICZM in the considered cases.