Purpose - The purpose of this paper is to deal with the design of passive filter for power electronics voltage inverters used in aircraft electrical drives (a permanent magnet synchronous machine fed by a six-phase voltage inverter with PMW control), using optimization for both sizing and sensibility analyses. Design/methodology/approach - The approach is generic. An aid allows to modify easily the frequency model and so to check various study cases, and to carry out the filter optimization for different topologies or control strategies. Findings - The approach is generic. An aid allows to modify easily the frequency model and so to check various study cases, and to carry out the filter optimization for different topologies or control strategies. Research limitations/implications - The power electronics load is supposed to be a set of predefined harmonic sources, obtained by experiment or time simulation plus fast fourier transformation before the optimization process. Practical implications - The problem has numerous constraints on the components, mainly technological constraints. The volume is minimized, respecting electromagnetic standards and an electro magnetic interference filter prototype has been made. Originality/value - The frequency model is automatically generated. A complex aircraft application has been studied thanks to the approach. Several sensibility analyses have been carried out. An EMC filter has been sized and an experimental prototype has been made, comforting the sizing by optimization.