A method to correctly measure the dispersion of an optical fiber as a function of wavelength is proposed and demonstrated by utilizing the partially degenerate four wave mixing process. This is done for a highly nonlinear fiber for which the dispersion values are very small and there is no prior knowledge about the zero dispersion wavelength. Powers in the idler frequencies are measured for different values of wavelength separation between the pump wavelengths to extract the dispersion map of the highly nonlinear fiber. © 2011 SPIE-OSA-IEEE.