The analysis of electrically large planar conducting structures is examined by employing parallel computations of an integral equation technique in conjunction with a method of moments. The integral equation, in terms of the induced conductivity currents, is solved using an entire domain Galerkin technique, with Chebyshev-type basis functions. The resulting algorithm parallelization enables extension of the proposed methodology above the resonance region. Numerical results are computed for several scatterer sizes and excitations source types on varying high-performance computing platforms: Silicon Graphics Power Challenge, Intel Paragon XP/S, CRAY C-90, and CRAY T3D. A comparison is made among these diverse computing platforms for their applicability-suitability in solving electromagnetic problems in the domain of electrically large planar scattering structures. Their suitability is not only judged on performance obtained but also on ease of code portation. ¿ American Geophysical Union 1996