A new technique, generalized differential quadrature (GDQ), is applied to determine the propagation characteristics of hollow metallic waveguides of square, rectangular, circular, and elliptical cross sections. The results show excellent agreement with theoretical values. The GDQ is compared with surface integral formulation (SIF) and the conjugate-gradient method (CGM) and is shown to have high accuracy, speed, simplicity and efficiency. (C) 1997 John Wiley & Sons, Inc.