Traditional fermented foods prepared using milk, cereals, and pulses occupy a pivotal position in the dietary practice of people of India's western states Gujarat and Rajasthan. Fermented foods such as dahi, chhash, raita, shrikhand, dhokla, khaman, handvo and khandvi are consumed routinely and are associated with the traditional customs and beliefs of people of these two states. Dahi, chhash, raita, and shrikhand are fermented milk products, whereas dhokla, khaman, handvo, raabadi and khandvi are prepared using cereals and pulses. These popular traditional foods are valued for their high nutrition and possible therapeutic value and relished for their characteristic flavour and palatability. Lactic acid bacteria and yeasts are the major groups playing a crucial role in the fermentation of these foods. Production of most of these products is still largely confined to home and by unorganized sector, mainly by small dairy farms. Recently several large cooperative dairies and organized sectors have started manufacturing dahi, buttermilk, and shrikhand on large scale and are having good market. The limited shelf life of these foods at room and refrigeration temperature is a major constraint in their effective marketing. Researchers have tried various techniques for preparation and extending the shelf life of some of these ethnic foods.