Abstract The manufacturing cost of WT blade is about 15–20% of wind turbine production cost. The expenses of innovations in design of blades represent the small amount of overall cost of wind turbine production. Profits coming from better structural model, use of suitable composite materials and better techniques of manufacturing, both the blades and composite materials, causes necessity of application of numerical modeling and optimization techniques. When designing a wind turbine, the goal is to attain the highest possible power output under specified atmospheric conditions. From the technical point of view, this depends on the shape of the blade. The change of the shape of blade is one of the methods to modify stiffness and stability, but it may influence aerodynamic efficiency of wind turbine. Other method to change dynamic and mechanical properties of wind turbine is modifying the composite material, which the blade is made of. The problem of determining the optimal shape of blade and determining the optimal composite material is a complex one, as the mathematical description of aerodynamic load is complex and a number of constraints and objectives have to be satisfied. These considerations have prompted the authors to take up the problem of the multi-criteria optimum design of wind turbine blades. The aim of this study was to develop a computer program package that would enable optimisation of wind turbine blades with regard to a number of criteria.