The specific surface area of two tobacco blends, a dark air-cured and a Virginia, have been measured by the conventional methodology using Kr gas. In an independent set of experiments, the isotherms of water adsorption have been determined for different tobacco types, namely Flue-cured, Burley, Oriental, Dark air-cured, Midrib and Reconstituted tobacco. The experimental data are compared with the scarce data found in the literature showing a close agreement. Both types of isotherms have been analyzed by using the BET equation. Large differences in specific surface areas are found for the two types of molecules used that can not be explained from the physisorption model. Also differences between the different types of tobaccos measured are noticed, showing the influence of the type of curing in the adsorption properties of the tobacco leaf.