Fermentation is a method of food preparation to develop desirable characteristics, flavor, aroma, texture, and keeping quality. Certain bacteria, yeasts and molds have adapted to protect foodstuffs from changes by other microorganisms and to retain essential nutrient substances. Various fermentation processes are interrelated. The microbial, physical, chemical, and organoleptic changes are important to mankind. Growth and fermentation by several species of microorganisms usually develop in sequence. Fermentation is an inexpensive, effective means of food preservation that could be utilized in alleviating world food problems. The ultimate goal of research and fermentation studies should be control, inhibition, or elimination of undesirable microbial species concomitant with favoring growth and fermentation by desired species. Specific fermentation processes for milk, vegetables, sausage, cereal, alcohol and spices are discussed