The hydrogen evolution reaction (HER) was studied on electrodeposited Ni-P alloys containing 7, 20 and 28 at.% P. Potentiodynamic, potentiostatic and impedance spectroscopy measurements were performed in 0.1 M H2SO4 solution. Kinetic parameters of the HER were derived from the analysis of polarisation and impedance data. Crystalline Ni-7P alloy showed higher rate of the HER than amorphous Ni-20P and Ni-28P samples. However, this difference was small. The evident increase of the rate of the HER was observed for the crystalline Ni-7P upon anodic prepolarisation. Under these circumstances the nature of the HER was changed and very high values of interfacial capacitance and much lower values of Tafel slope were found. These high values of interfacial capacitance can be assigned to the onset of a porous phosphate film on the alloy surface.