On rape pods (siliques) sorption of water vapour was investigated. The pods of variety Star spring rape were taken from plants at full maturity growth stage. Two kind of pods with various resistance to breakage, i.e., easily breakable and more resistant, were used. The results are presented as sorption-desorption isotherms. Brunauer-Emmet and Teller (BET) equation was used to analyse the experimental sorption data. All the isotherms belong to type II according to BET classification. For both kinds of pods the amount of sorbed water was similar, although for the easily breakable pods a slightly larger amount of sorbed water was observed. To obtain estimates of surface area, the sorption isotherms were analysed using the BET equation, according to Polish Standard PN-Z-19010-1. The average surface area of the rape pods evaluated from sorption isotherm was about 260 m2 g-1, whereas it was equal to 290 m2 g-1 when desorption data was used. Generally, easily breakable pods exhibit more pronounced sorption of water vapour, hystersis loop, and specific surface area.