ABSTRACTThe world's smallest porpoise—the vaquita (Phocoena sinus)—is on the brink of extinction. Endemic to the upper Gulf of California, it has dwindled to fewer than 19 individuals in 2023. The primary source of mortality is drowning in gillnets set for totoaba (a giant croaker fish). Our review of the past 50 years of efforts to simultaneously attain conservation goals for the vaquita and economic and social goals for the fisheries concludes that they have consistently failed to meet the lowest expectations of any stakeholders. The time has therefore come to recognise that the only solution to this problem is to make an immediate and definitive decision: either preserve the vaquita or bolster sustainable fishing in the upper Gulf—and accept the associated social, economic, and political costs of either choice.