In the last decades, the increasing use of the power electronic devices in space and military applications has led to the reliability analysis of DC-DC power converters. In this paper the design of a quadratic DC-DC converter has been performed in order to improve both reliability and efficiency. The design is performed by the minimization of objective functions using the GA heuristic algorithm, in order to identify the optimum values of the converter parameters that ensure the desired reliability. A complete reliability analysis of the quadratic converter has been done and the proposed design methodology has been demonstrated by simulation.