Wildlife (bushmeat or game) is the primary source of protein for most poor households in tropical forests, and its consumption is resulting in unsustainable hunting of large animals, even in isolated regions. As a result, loss of fauna is often a more immediate and significant threat to the conservation of biological diversity in tropical forests than is deforestation. Although the potential effects of the extirpation from tropical forests of large, seed predating and seed dispersing wild animals is poorly understood, it is likely that there will be irrevocable changes in the structure and function of these ecosystems. We carried out a survey of 510 households of Tsimane' Amerindians in the rainforest of Bolivia to investigate how the prices of game and meat from domesticated animals affect the consumption of game. The results indicated that the price of fish and meat from livestock is positively correlated with consumption of wildlife, suggesting that policy makers may be able to reduce the unsustainable hunting of wildlife for food by reducing the price of fish and the price of meat from domesticated animals relative to that of wildlife. Increasing the production of livestock without causing environmental degradation will require long-term public investment in agricultural research and extension, and substitution of fish for game meat in the absence of sustainable management regimes will result in over-exploitation of riverine and lacustrine fish stocks.