Some design optimisation results of a permanent magnet synchronous motor (PMSM) are presented in this paper. The experimental software environment PASCOSMA (Programme d'Analyse de Synthese deConception et d'Optimisation de Systemes Modélisables Analytiquement) [3], developed at the Laboratoire d'Electrotechnique de Grenoble (LEG, Grenoble, France), has been used to generate the optimisation programme. The programme is dedicated to automatise the design process of an electrical machine or device. The optimisation programme is generated as a result of the analysis and transformation of the chosen design algorithm for the optimised machine. In the paper the basic assumptions of the chosen design algorithm for PMSM, the objective function, and some results of the PMSM optimisation obtained by PASCOSMA have been described. The main dimensions of the PMSM: the inside stator diameter (dri), effective length of the stator core (les) and air gap ( ) are calculated using equations (1)-(3). The volume of the all permanent magnets is estimated by equation (4), where Pn. is the rated power. The sum of the magnet volume, electromagnetic torque and power losses, being multiplied by an adequate coefficient, is the objective function - given by equation (13).