Abstract Magnetization measurements in Pr 2NiO 4 single crystals were made up to 70kOe, for different orientations of the applied magnetic field with respect to the crystallographic axes, in the range from 1.5 to 300K. The Ni sublattice becomes antiferromagnetically ordered at T N =325 K, as reported from previous neutron diffraction experiments 1. There is also a structural transition at T C1 =117 K 1, which allows a ferromagnetic component in the low temperature phase. Below T C1 different magnetic anomalies are observed, which have been interpreted as spin reorientations. Finally at low temperature the Pr sublattice is also ordered. Four different transitions induced by the external applied magnetic field parallel to the c-axis are visible in the range from 0 to 70 kOe, for T<T C1. The temperature dependence of the critical fields is also obtained in the range from 1.5 to 90K.