Based on thorough bibliographic research of a highly controversial topic, this report, jointly sponsored by IUCN, UNEP and WWF, shows the potential of plantations, while also exposing problems which may arise if massive tree plantations proposed for the tropics are to be established. Major issues covered include; species selection, soil and water cycle effects, fires, pests and diseases, effects on biodiversity, carbon dioxide fixation, land tenure and social issues, and plantation economics. Some broad conclusions and guidelines to be considered when establishing large scale plantations in the tropics complete this study.