The paper presents the variation of structure and magnetism observed with the A-site composition of the double perovskite oxide Sr2-xPrxFeCoO6 (x = 0, 1, 2). The lattice symmetry was found to be lowered from tetragonal (x = 0) to orthorhombic (x = 2). With a ratio 1:1 of Sr and Pr, a highly asymmetric monoclinic structure is observed. The magnetic behavior of the middle member (x = 1) shows resemblance with that of Sr2FeCoO6, indicating the effect of Sr in the dilution of rare earth magnetism. © 2018 Author(s).