Ecodesign is the integration of environmental considerations at the design phase, considering the whole product life cycle. Expert systems are very helpful for implementation of the ecodesign. The very first such system in Latvian was developed as a master’s thesis at the Institute of Energy Systems and Environment. A particular effort was made to show the relation between material choice in a product and the product’s environmental impact. The developed system uses the basic guidelines of eco-design, EU legal restrictions concerning production of the electric and electronic products, and requirements of stakeholders. The environmental impact of materials used in products was evaluated to help manufacturers to carry out eco-design and make the right decisions concerning materials in the analysed products. The user of this tool can evaluate product’s conformance to ecodesign guidelines and to the requirements of Europe’s ecolabel “Ecoflower”. The well known “Eco-Indicator’99”method was used in the new expert system to evaluate environmental impact of materials. In addition, the new tool gives a short description of polymers, metals and other materials to help the user to identify and increase competence about various materials which could be used in the product. Although the completed methodology was targeted primarily at electric and electronic products, it is relatively universal and can be used by other product manufacturers as well. Because the new expert system is simple and requires no specialized computer knowledge or ecodesign skills, it can be used as a teaching aid for ecodesign courses at universities. A description of the instrument and results of its application, and suggestions for further development are provided in the paper.