Sorption isotherms of pea seeds with three different treatments were measured by equilibrium relative humidity (ERH) determination technique at five temperatures. Four ERH models with a temperature term and the GAB model were adopted to evaluate the goodness-of-fit of sorption isotherms. Sorption data from literature were also selected to compare the effect of varieties on the sorption isotherms of pea seeds. The result of this study indicated that pea seeds revealed a hysteresis and that treatment temperature affected the sorption isotherms. The Modified-Henderson equation was an adequate model for the sorption data of three treatments used in study. No universal or best sorption model was found for the isotherms of pea seeds from published data. The GAB model was not a good model when applied to the sorption properties of pea seeds. (C) 2002 Elsevier Science Ltd. All rights reserved.