The magnetization of 8 disordered Pt‐Ni alloys containing 32 to 60 at.−% Ni and of 4 ordered Pt‐Ni alloys containing 38 to 50 at.−% Ni has been measured in magnetic fields up to at least 56 kG (and usually up to 87 kG) and at temperatures of 1.5 and 4.2 K. The magnetization data of the samples can be fitted by straight lines on an Arrott plot. Below ∼ 44 at.−% Ni, the disordered alloys appear to be exchange‐enhanced paramagnets with large magnetic susceptibilities which increase strongly as the critical composition for the onset of ferromagneti sm is approached. Ordering of the samples nearest the order‐disorder composition, NiPt, greatly reduces their susceptibility. Above 44 at.−% Ni, the disordered samples are ferromagnetic, with large susceptibilities which again increase strongly as the critical composition is approached. Ordering of these samples makes them paramagnetic with susceptibilities comparable to those of the other ordered samples. Contrary to the behavior of most order‐disorder magnetic systems, atomic order in NiPt is associated with magnetic disorder.