A simple, flexible, pantropical forest classification framework is proposed to provide a common platform for foresters, vegetation mappers, climatic modellers, biogeographers and plant ecologists. The framework is provided by bioclimatic types, defined on annual rainfall, seasonality and mean temperature of the coldest month. Within each bioclimatic type a series of forest formations occurs, defined on forest structure and physiognomy. The formations are pantropical. The main schemes of forest classification published for continental Asia, the Malay Archipelago, America and Africa are given in Tables 1-4, set against this bioclimatic framework. Different authors have used different names for forest formations and is unlikely to ever be general agreement on nomenclature. Floristic composition varies across continents and regions. For some purposes it is useful to divide bioclimatic types into ecofloristic zones. The correspondences given in this paper are between bioclimates and forest formations in the absence of anthropic impacts. (C) 2000 Elsevier Science Ltd. All rights reserved.