Within the context of integrated coastal area management (ICAM), this research investigates the complexity of horizontal and vertical institutional relationships in the case of Croatia. There are three aspects, namely sectors, areas and levels that represent a basis for developing a methodological approach for evaluating ICAM approaches. It is questioned, if this specific management approach adds to the complexity of development management in general or does it contribute to better and more sustainable implementation of existing plans in coastal areas. The main thesis of this research is that coastal area management approaches should rather concentrate on implementation of concrete strategic projects and contribute to implementation of existing plans. The creation of just another plan or strategy, which is not implemented, should be avoided. Due to the complex management requirements, ICAM calls for an evolutionary and process oriented approach. Only visible results that derive from implemented projects can enable institutions to learn how to plan and manage development in coastal areas more carefully in an integrated manner considering also a longer term perspective.