This review analyses the environmental evolution of the Ethiopian highlands in the late Quaternary. The late Pleistocene (20,000-12,000 C-14 years BP) was cold and dry, with (1) low lake levels in the Rift Valley, (2) large debris fans on the flanks of Lake Abhe basin, and (3) the Blue Nile transporting coarse bedload. Then, a period with abundant and less seasonal rains existed between 11,500 and 4800 C-14 years BP, as suggested by increased arboreal pollen, high river and lake levels, low river turbidities and soil formation. Around 5000-4800 C-14 years BP, there was a shift to more and conditions and more soil erosion. Many phenomena that were previously interpreted as climate-driven might, however, well be of anthropic origin. Thick sediment deposits on pediments as well as an increase of secondary forest, scrub and ruderal species in pollen diagrams are witnesses of this human impact.