A new approach to obtain ultra-flattened-chromatic-dispersion-optical- fibers by introducing a small airhole at the core of a conventional step-index-optical-fiber is presented. The proposed structure exhibits a simple geometry and has been analyzed through a vectorial finite element method in conjunction with genetic algorithm. The structure parameters are optimized using genetic algorithm to obtain ultra wideband residual dispersion compensation. Numerical results show that the optimized model exhibits flattened negative dispersion over E + S + C + L + U wavelength bands with an average dispersion of -253 ps km-1 nm-1. Copyright © 2011 Wiley Periodicals, Inc.