The vibration of a helicopter has several different sources, such as the rotor, engine and transmission system. This creates a number of problems with performance, for example poor manoeuvrability, discomfort of the pilot, low fatigue life of the structural components, and, consequently, high operating costs. At the present time there are in existence various methodologies for vibration reduction, such as Higher Harmonic Control (HHC), Individual Blade Control (IBC), Active Control of Structural Response (ACSR), Active Twist Blade (ATB), and Active Trailing-edge Flap (ATF). The goal of the presented work is the development of an active twist actuation concept based on the application of Macro Fiber Composite (MFC) actuators. These actuators consist of polyamide films with IDE-electrodes. They are glued on the top and the bottom of piezoceramic ribbons and oriented at ±450 to the spar axis of the rotor blade. The interdigitated electrodes deliver the electric field required to activate the piezoelectric effect in the fibers and this, in turn, creates a stronger longitudinal piezoelectric effect along the length of the fibers. The properties and orientation of piezoelectric actuators cause the MFC actuators to induce shear stresses and thus distribute a twisting movement along the blade. The design methodology, based on the planning of experiments and response surface technique, has been developed for an optimum placement of Macro Fiber Composite (MFC) actuators in helicopter rotor blades. The optimisation problem for the optimum placement of actuators in helicopter rotor blades has been formulated on the results of parametric study. The investigated helicopter has a rotor blade which is equipped with NACA23012 airfoil and has a rectangular shape with an active part radius of 1.56 m and a chord length of 0.121 m. The blade also consists of D-spar. This is made of unidirectional fiberglass, reinforced plastic (UD GFRP), a skin made of ±450 GFRP, a foam core, balancing weight and MFC actuators placed on the top and bottom of the skin. The 3D finite element model of the rotor blade has been built by ANSYS. The rotor blade skins are modelled with linear layered structural shell elements (SHELL99), balancing weights and foam with 3D 20-node structural solid elements (SOLID186). The spar is modelled with shell and solid elements. The optimisation results have been obtained for design solutions, connected with an application of active materials, and checked by the finite element calculations.