Tropical forests are vital for global biodiversity, carbon storage and local livelihoods, yet they are increasingly under threat from human activities. Large-scale land acquisitions have emerged as an important mechanism linking global resource demands to forests in the Global South, yet their influence on tropical deforestation remains unclear. Here we perform a multicountry assessment of the links between large-scale land acquisitions and tropical forest loss by combining a new georeferenced database of 82,403 individual land deals—covering 15 countries in Latin America, sub-Saharan Africa and Southeast Asia—with data on annual forest cover and loss between 2000 and 2018. We find that land acquisitions cover between 6% and 59% of study-country land area and between 2% and 79% of their forests. Compared with non-investment areas, large-scale land acquisitions were granted in areas of higher forest cover in 11 countries and had higher forest loss in 52% of cases. Oil palm, wood fibre and tree plantations were consistently linked with enhanced forest loss while logging and mining concessions showed a mix of outcomes. Our findings demonstrate that large-scale land acquisitions can lead to elevated deforestation of tropical forests, highlighting the role of local policies in the sustainable management of these ecosystems.