The aim of this study was to investigate the applicability of the GAB equation in the description of sorption properties of freeze-dried Brussels sprout at the temperature rancing from 0 to 40^oC. The values of constants C and K as well as the values of mean relative deviation P show that the GAB equation well describes the adsorptivity of freeze-dried Brussels sprout in the whole range of water activity. Isotherms are the closest to type II according to the BET classification. The calculated capacity of a monolayer ranged from 7.3 to 8.1 g H₂O/100g d.m. The effect of temperature on moisture content was observed only at the water activity ranging from 0 to 0.2 and 0.75 to 0.98. In these intervals, lower equilibrium moisture contents corresponded to higher temperatures. Low positive values of pure isosteric heat of sorption in the range of high moisture contents show an exothermic interaction of water with a matrix.