Environmental problems encountered in most of the developing countries arise due to conditions of poverty and under development as well as the negative effects of development progrmmes which have been badly planned and implemented. In most of the developing countries, particularly those in the humid-tropical region, damage being done to the environment, because of the population size and its increase and the scale of developmental activities, is of such magnitude and consequences that urgent remedial measures are called for. Environmental impact assessment (EIA) has been identified as a major tool for the realization of environmentally sound development. Over the last decade EIA systems have been or are being implemented in many developed as well as developing countries. This synthesizes the practical experiences in the application of EIA systems to outline data problem requirements and analysis for developing countries in the humid-tropic region.