In Al-free PrBa 2 Cu 3 O 7−y single crystals the kink in the temperature dependence of magnetic susceptibility χ ab (T ), connected with Pr antiferromagnetic ordering, disappears after field cooling (FC) in a field H ab-plane. The kink in χ c (T ) remains unchanged after FC in H c−axis. As a possible explanation, freezing of the Cu magnetic moments, lying in the ab−plane, caused by FC in H ab, hinders their reorientation and, due to coupling between the Pr and Cu(2) sublattices, ordering of the Pr 3+ moments. A field induced phase transition and a field dependence of the Pr 3+ ordering temperature have been found for both H c and H ab.