Tropical forests are under severe threat from over-hunting. Subsistence harvests and poaching have decimated wildlife populations to the extent that nearly 50% of Earth’s tropical forests are partially or fully devoid of large mammals. Declines are particularly acute in Southeast Asia where ongoing defaunation, largely attributable to indiscriminate snare trapping, is widespread. Using the extensively forested Aceh province in northern Sumatra as a case study, we document rampant snaring, which threatens Earth’s last sympatric population of tigers, rhinoceros, elephants, and orangutans. To prevent catastrophic hunting-induced impacts already experienced in mainland Southeast Asia, we call for more comprehensive conservation planning assessments that strengthen wildlife law enforcement, promote collaborative anti-poaching, and research species-specific snaring impacts, particularly in the context of human-wildlife conflict. We conclude with a discussion of the important linkages between poaching, wildlife trade, and zoonotic disease risk.