Salting is one of the oldest preservation methods to increase the shelf life of fish. Some of the factors which affect the mass transfer behaviour are muscle type, fat content and fat distribution in the muscle. This work shows the differences in mass transfer kinetics for two fish species (cod and salmon) during salting with two brine concentrations (15% and 25% w/w). Results indicate that there are significant differences depending on the fish type. The different behaviour seems to be associated with the fat content which represents a barrier to transport of water and NaCl. When total net weight changes for salmon were expressed on a fat free basis, the kinetic parameters for salmon became quite similar to those obtained for cod. Considering the diffusivity of NaCl in the fish liquid phase, the higher diffusion coefficients were obtained when working with Atlantic salmon. (c) 2006 Elsevier Ltd. All rights reserved.