Abstract We have studied the magnetic structure of the oxygen reduced YSr 2Cu 3− x Fe x O 6+y (x=0.8 and 1) compound. Three-dimensional (3D) long-range antiferromagnetism was observed and was indexed with propagation vector k=( 1 2 1 2 1 2 ) . The only peak with non-zero intensity was ( 1 2 1 2 3 2 ) . The temperature variation of the thermal average magnetic moment per site showed a complicated structure probably due to the different temperature variation of the magnetic moment at the Cu(1) and Cu(2) sites. The Mössbauer data were fitted taking into account an Fe ordered moment at the Cu(1) sites.