The radial basis function generatedfinite difference (RBFFD) method is applied to the analysis of homogenous waveguides. To this end, the Helmholtz equation and the bound ary conditions are collocated on the waveguide cross section. At each collocation node, derivatives are locally approximated by RBFFD formulas based on polyharmonic splines supplemented with highdegree polynomials. As a result, a sparse matrix eigenvalue problem is obtained which allows cutoff wavenumbers and axial fields to be calculated. To illustrate the accuracy of the method, we consider a semicircular and an eccentric circular waveguides.