Wood industry is a very important part of both the Greek Rural and industrial sector. The discovery of the differentiation in the level of growth and in the quality of financial management between the Greek wood companies can provide very important aid in the design of an effective rural development policy. The evaluation and ranking of Greek wood companies based on actual financial data is a very complicated task and it requires expertise knowledge and skills. On the other hand a computer expert system can perform validation and evaluation in an efficient way and can substitute human experts. An expert system was designed and developed towards this direction. It uses multicriteria analysis for each one of the wood companies based on actual financial data and it applies fundamental principles of fuzzy logic in order to calculate the expected intervals of flows for the following years.