Osmotic dehydration of button mushrooms (Agaricus bisporus) slices carried out done by dipping them in brine of different concentrations of salt (10%, 20% and 30%), mass ratios (1/10 and 1/25 w/w) solution at a temperature of 60°C, and duration of 30 minutes. With respect to water loss (WL) and salt gain (SG), with the increase in concentration of salt, the water loss increased and the solid gain decreased. The quality of dehydrated slices were evaluated on the basis of moisture per cent, non-enzymatic browning, rehydration ratio and colour values. The lowest moisture content (6.3%) and non-enzymatic browning (0.37) and highest rehydration ratio of 2.68 respectively was observed in treatment T6 (containing salt 30g and mushroom to solution ratio of 1:25) nad thus, was the best.