Soy protein and soy fiber are common ingredients in many foodstuffs. Various kinds of soy protein, including soy flour, soy-protein concentrate, and isolated soy protein, are currently used in human foods. Soy proteins are used in infant formulas and enteral nutrition products, as ingredients in meat products, and as protein supplements. Although it is a plant protein, the protein quality of soy protein is excellent. Soy fiber is used in enteral nutrition products and some bakery goods. Research shows that soy fiber provides the important health benefits usually associated with dietary fiber, including improved laxation and cholesterol-lowering ability. This review provides background information on soy protein and soy fiber and their use in human foods.