This paper assesses three sustainable de- velopment strategies – the European Union’s Sustainable Development Strategy in its revised version, the Mediterranean Strategy for Sustain- able Development and Slovenia’s Development Strategy – according to the level of sustainability these strategies provide. Deriving from three di- verse sustainable development regimes, select- ed strategies are scrutinised for the presence of the five general principles of effective sustainable development strategies promoted by the United Nations and the Organization for Economic Co- operation and Development. Building on George and Kirkpatrick’s (2006) framework for analysis, we concentrate on principles of strategic planning and sustainable development, and a coordinated set of measures to ensure their implementation. The results reveal that the major differences be- tween the assessed strategies are present in the sophistication of the theoretical bases and the integration of three main pillars of sustainable development (i.e. environmental, economic and social). In general, the assessed strategies re- flect a high degree of inclusiveness of a variety of interests. However, there is a common weak- ness among them in terms of implementation, be it in the provision of adequate resources, the guarantee of adequate implementing capacity of the institutions designated for implementation or the precise definition of the institutional frame- work responsible for the implementation of the strategy.