The Finnish power company Teollisuuden Voima Oy studies crystalline bedrock in Finland for final disposal of high-level nuclear fuel waste. In evaluation of the varying lithological and structural conditions CAD-based ROCK-CAD system has been developed. ROCK-CAD is based on true solid modelling approach. One modelled volume consists of several mutually independent submodels. Mainly lithological, structural (fracturing) and hydraulical properties are modelled. ROCK-CAD is in operational use and experiences have been got from four sites modelled this far. The main uses of the software, have been in general visualization, in planning of sopplementary investigations and in qualitative interpretation and model development done by the experts. Computerized models form also the basis for ground water flow simulations and rock mechanical calculations. Two example drawings are presented and discussed.