In this paper expert systems and geographical information systems technologies are combined to help with an implementation of a land suitability evaluation model. The result is the LEIGIS software, which allows empirical work within the framework of this paper. The model used is based on the FAO land classification for crops, and data which describe an agricultural area in terms of soil mechanics and environment. The land evaluation has two parts; the physical evaluation and the economic evaluation. For the physical evaluation of the land, data for 17 land characteristics have been used and a Boolean classification method has been applied. The implementation includes models for general cultivation and five (wheat, barley, maize, seed cotton, sugar beet) specific crops. A new interpolation function is introduced to map values to scores in terms of land characteristics. The economic evaluation includes income-maximization taking into account market restrictions. The expert system has been designed to help with the evaluation of land and to allow alteration in its rules based on different performance observed in local areas. The GIS functions help in managing the spatial data and visualizing the results. The software developed allows the evaluation and presentation of any equivalent spatial dataset and does not require special computer skills.