Moisture diffusivity (Dm) and drying constants (k) of food products, raw and processed, are reviewed. These mass transfer properties were classified into various commodity groups such as fruits and vegetables, cereal products, meat products, gels, etc. These properties were also reviewed for the foods during frying process. Limited data on Dmare available in literature, with a large variation of the reported values, due to the complexity of the foods and various methods of determinations used. These methods to determine Dmand k are also discussed in brief. The data on the activation energy of diffusion (?H) process are also reviewed for various food products. Many of these properties are summarized in various tables for easy reference. Various mathematical models used to describe these properties are also given when available.