Unmanned Aerial Vehicles are often used as tactical surveillance tools, or for reconnaissance purposes. In both roles, the acoustic shiftiness is an essential feature for the success of the mission. Micro Aerial Vehicles (MAVs) are also deployed in civilian roles and are flown in close proximity to populated areas. In hover, the inflow velocity is small and the propeller must provide high thrust to support aircraft weight. Moreover, most of MAVs are equipped with electric motors, that contribute to simplify operations and significantly reduce their noise signature. Since the main acoustic source of electric motor-equipped MAVs is the propeller, there is a renewed interest in reducing the noise produced by small rotors. Reduction of the propeller noise requires special attention in the design process, as rotor efficiency maximization and its acoustic signature minimization might be contradictory goals for which the best compromise must be found. This project shows the results of the design process of a silent propeller.