Ammonium chloride-impregnated and untreated almond shell and hazelnut shell samples were carbonized in a flow of nitrogen at relatively low temperatures. Pore structure characterization and sorption capacities of activated carbons prepared from shells of almond and hazelnut indicated that treatment with NH4Cl increased the total surface area and improved sorption characteristics. Chemical activation carried out at 350-degrees-C gave products with surface area values above 500 m2 g-1. On the other hand, the surface area values observed for the products obtained from untreated raw materials were about half of this value. The surface area of products obtained from NH4Cl-impregnated samples reached values of over 700 m2 g-1 when the carbonization temperature was increased 700-degrees-C.