The impacts of forest certification costs on the output, price, and trade of forest products were assessed via computable general equilibrium modeling under various scenarios representing tropical, temperate, and global forest certification. Despite causing more severe and extensive impacts, global certification seems more acceptable than regional certification to major timber-producing countries. The regions that would suffer the most from global certification would not be major timber-producing regions, but major net importers of forest products like East Asia. With 5%–25% increases in forestry production costs resulting from certification, the world's forestry output would decline by 0.3%–5.1%, while the world price would rise by 1.6%–34.6%; impacts on global lumber and pulp and paper markets would be much more moderate. In general, forest certification would have larger impacts on trade and price than on output. While causing trade diversion and substitutions between tropical and temperate forest products and affecting regional forest product markets, forest certification would not substantially induce substitutions between wood and nonwood products at the global aggregate level. Because of the possible leakages (deforestation elsewhere) associated with regional certification and the land-use shifts resulting from sectoral production shifts at the regional level, forest certification may not necessarily curb tropical deforestation.