Vickers microhardness measurements have been performed on (112) faces of n-and p-type CuInSe2single crystals at room temperature. In nearly stoichiometric samples, hardness values of 2·33 ± 0·06 GPa and 3·37 ± 009 GPa were found for n-and p-type material respectively. Preliminary results regarding hardness anisotropy and microhardness changes due to larger deviations from stoichiometry are given. At applied loads in the range 5–500 g no dependence of the microhardness on the load was found.