This work is closely connected to the paper: K.G. MAHMOUD, H.W. ENGL and HOLZLEITNER: "OPTIMUM STRUCTURAL DESIGN USING MSC/NASTRAN AND SEQUENTIAL QUADRATIC PROGRAMMING", Computers & Structures, Vol. 52, No. 3, pp. 437-447, (1994). In contrast to that paper, where thickness optimization is described, here the shape of two dimensional parts with different thickness areas will be optimized. As in the previos paper, a methodology for structural optimization using the commercial finite element package MSC/NASTRAN for structural analysis is described. Three different methods for design sensitivity analysis and gradient calculation are used, together with sequential quadratic programming with an active set strategy for optimization. The optimization and sensitivity analysis modules are efficiently coupled with MSC/NASTRAN using DMAP (direct matrix abstraction program) statements. To demonstrate the feasibility of the proposed methodology, the shape optimization of a unit injector rocker arm is presented as an example.