WP/SiO2 catalysts promoted with Ni were prepared by wet impregnation with various molar ratios of Ni to W and then evaluated in the reaction of pyridine hydrodenitrogenation for pyridine conversion and product selectivity. The addition of Ni to the WP/SiO2 catalysts resulted in increased pyridine conversion and selectivity to pentane. The molar ratios of Ni:W:P are important, because nickel and tungsten compete for phosphorous and form WP, W3O, Ni2P and/or W crystals.