Cereal grains form a major source of dietary nutrients for all people, particularly those in the developing countries. However, compared with animal foods, nutritional quality of cereal grains is inferior due to lower protein content, deficiency of certain essential amino acids, lower protein and starch availabilities, and the presence of some antinutritional factors. Fermentation of cereals for a limited period of time improves amino acid composition and vitamin content, increases protein and starch availabilities, and lowers the levels of antinutrients. In this review, the available literature concerning the nutritional improvement of cereals by fermentation has been compiled and is critically analyzed. The traditional foods prepared by fermentation of cereals in different parts of the world are briefly described and future research needs to improve their nutritional contribution are addressed.