The pilot study on estuarine management was initiated by the NATO Committee on the Challenges of Modem Society (CCMS). The objective of this project was to make a comparison of several estuarine management strategies and to formulate a set of recommen dations and planning guidelines to restore polluted estuaries, to prevent further estuarine deterioration, and to manage conflicting demands stemming from human activities. The first results of this NATO-CCMS project were reported in 1982, describing six estuaries and their management approaches. In 1985 CCMS decided a subsequent research project should be performed to achieve the original objectives. This second research project was basically done by way of a comprehensive questionnaire that was sent to authorities of estuarine areas all over the world. Eleven questionnaires have been received. In some instances, the questionnaires were not fully completed for several reasons. Especially, data on water quality was lacking. As a result, less attention will be paid to related aspects as originally intended. This study shows that knowledge of the number of functions and conflicts of estuaries may provide relevant information concerning the severity of the problems as well as the propensity towards planning of water systems.