Much careful work and thought are needed from the time an ore is discovered until a marketable product is produced. Most often, incomplete or imprecise information on the deposit must be used to decide to continue or not with the development and implementation of a project. This paper presents a diagnostic methodology to deal with gold projects at the preliminary stages. We have developed "lntelliGold"-an expert system for gold process design. A knowledge base on gold mineralogy and processing is used to provide the user with feasibility information on a given gold ore. Decision-makers can have a preliminary, yet reliable view of the mineral processing project, based on lab results supported by mineralogical characteristics, operational issues and economic analysis.