The Case Study Zagreb is the title of a project developed in the framework of the Inter-Agency Programme on the Assessment and Management of Health and Environmental Risks from Energy and Other Complex Industrial Systems. The programme, jointly undertaken by four UN organizations (UNEP, WHO, IAEA and UNIDO) aims at promoting and facilitating the implementation of the risk assessment and management methodologies. Therefore, the main purposes of the Case Study Zagreb Project is to assist, together with other similar activities undertaken within the existing Environmental Policy Plan for the city of Zagreb, in defining the optimum method of risk management in the area, improving the level of knowledge in the field, enhancing the ability of relevant institutions to react in an appropriate fashion in the event of various kinds of accident in energy plants and other complex industrial installations. Another aim of the Project is to assist in the industrial development of Zagreb with maximum control and risk management linked with such development. Such ambitious objectives of the Project, its comprehensiveness and integrality, underline its complexity and synthetic features. In other words, one of the basic requirements was that the results of the previous studies and analyses in the field should be made available. This very important requirement has been mainly met. Otherwise, the Project would have failed before even getting started. The paper reviews the Project development and its objectives and organization as well as all the activities carried out to date. Special attention is paid to the benefits of the Project team, in terms of experience gained and accomplishments made in the field. The Case Study Zagreb Project represents a very significant step forward in the implementation of the integrated area-wide approach to dealing with ecological problems in the large urban and industrial areas in the Republic of Croatia.