The solution of Maxwell's Equations in PVM environment is obtained to study the electromagnetic scattering about arbitrary shapes. The Lax-Wendroff Scheme is employed to solve the equations in time domain. The time domain values are then transformed to frequency domain, via FFT, to evaluate the Radar Cross Section, (RCS), of arbitrary shapes. The scattering of NACA 0012 airfoil and a generic helicopter fuselage are studied with overlapping and matching grids in resolving the space coordinates. The parallel solution efficiencies and speed-ups are high.