Chlorinated phenols are a kind of environmental priority pollutant that attract much attention. Nanosized Fe and Fe/Ni materials are considered as promising options for chlorinated phenol removal. The effect of Ni morphology on the removal of pentachlorophenol (PCP) with Fe/Ni nanomaterials was investigated in this study. Iron nanoparticles and nickel nanomaterials with different shapes were synthesized using a chemical reduction method and wet chemical techniques, respectively. The concentrations of PCP and chloride in solutions were measured with and without Ni present. The intermediates of PCP were also analyzed. The results showed that the dechlorination of PCP was promoted by Ni nanomaterials, among which the tubular porous Ni nanomaterials expressed the most promotion, then those with net shape and nanochains. However, the tubular porous Ni nanomaterials inhibited the removal of PCP, and the other two expressed a certain promotion. In the Fe/Ni system, Fe nanoparticles transformed into magnetite (Fe3O4) and/or maghemite (Fe2O3), and Ni nanomaterials were still pure Ni after reaction. The introduction of Ni nanomaterials would improve dechlorination of PCP, but the removal of PCP might be inhibited or improved as the morphology of Ni changed.