A genetic algorithm for ground-state structure optimization of a Palladium atomic cluster has been developed and ported on a SIMDMIMD parallel platform. The SIMD part of the parallel platform is represented by a Quadrics/APE100 consisting of 512 floating point units while the MIMD part is formed by a cluster of workstations. The proposed algorithm contains a part where the genetic operators are applied to the elements of the population and a part which performs a further local relaxation and the fitness calculation via Molecular Dynamics. These parts have been implemented on the MIMD part and on the SIMD one, respectively. Results have been compared to those generated by using a Simulated Annealing technique. © Springer-Verlag Berlin Heidelberg 1996.