We demonstrate a 10 Gbit/s nonreturn-to-zero wavelength converter based on four-wave mixing in a 20m highly nonlinear photonic crystal fiber. The tunable wavelength conversion bandwidth 3dB is about 100nm. The conversion efficiency is -16dB when the pump power is 22.5dBm. Phase modulation was not used to suppress the stimulated Brillouin scattering; thus the linewidth of the converted wavelength remained very narrow. The eye diagrams show that there is no additional noise during wavelength conversion. The measured power penalty at a 10-9 bit-error-rate level is about 0.7dB.