Dry tropical forests are important ecosystems, yet these forests are increasingly threatened, a new study discovers. An innovative approach to characterize how deforestation took place since 2000 showed that more than 71 million hectares of tropical dry forests were lost, particularly in South America and Asia. Even more worrisome, one third of remaining forests are under threat as they are located in so-called frontier areas where deforestation is progressing rapidly. African tropical dry forests are still comparatively less disturbed, but in many of them deforestation has recently emerged. Forward-looking monitoring and land-use planning is urgently needed to safeguard the world's tropical dry forests.