We experimentally demonstrate simultaneous all-optical regeneration of two 160-Gbit/s wavelength-division multiplexed (WDM) channels in a single highly nonlinear fiber (HNLF). The multi-channel regeneration performance is confirmed by bit-error rate (BER) measurements. The receiver powers at a BER of 10 -9 are improved by about 4.9 dB and 2.1 dB for the two channels, respectively. The BER performance is not degraded by the presence of a second channel. Mitigation of the inter-channel nonlinearities is achieved through bidirectional propagation.