Eutrophication of coastal marine environments is a widespread and transboundary problem necessitating consideration of measures to conserve and restore the marine environments that have been adversely affected. As of now, there exist no criteria set for eutrophication of coastal marine waters due to the difficulty to establish single national/international assessment criteria for eutrophication applicable to all coastal waters with different geographic and climatic conditions. However, there appear to be a number of joint and integrated studies among coastal countries to harmonise the outcomes of their scientific research and monitoring activities that might change the natural attributes of the environment. The common findings may then be utilised to develop guidelines on establishing eutrophication criteria together with application of policies and strategies. This Study attempts to review the recent efforts of certain groups gathered together and of some countries to develop and improve approaches for assessment of eutrophication in coastal marine waters. Studies of OSPAR Commission, USEPA, and Australia and New Zealand related councils will also be referred.