In this paper we present an iterated moment method (IMM) for evaluating dispersion relations of dielectric waveguides with arbitrary cross-section. The numerical results are given for the fibers of var ous shapes such as circles, ellipses, equi-lateral triangles, chipped-circles and egg-shaped cross-sections. The results agree well with exact computer-aided numerical results by finite element method and point-matching method. The present method is simple and saves computation time.