The placement of passive components significantly influences the EMI behavior of power electronic systems. Particularly filter components are affected by magnetic field coupling reducing filter performance. In this paper we introduce a novel approach for a methodical EMI design of power electronic circuits. Based on the results of EMI prediction design rules for component placement are derived. To meet the design rules a prototype of a dedicated placement tool was developed. This tool has much interactive and automatic placement functionality to solve the very complex design task efficiently. Using the proposed approach in the design stage allows both a statement on achievable performance with the given components and the minimization of the system volume. Development costs can be relevantly reduced.