X-ray diffraction and Mössbauer studies of perovskite BiFe Cr O and PbFe Cr Sb O solid solution ceramics, fabricated under high pressure (4–6 GPa) have been carried out. Two morphotropic phase boundaries were revealed in the BiFe Cr O system: one between rhombohedral (R3c) and orthorhombic (Pbam) phases at x ≈ 0.5–0.6 and the other between the orthorhombic (Pbam) and monoclinic (C2/c) phases at x ≈ 0.9. It was found out that substitution of Cr for Fe in BiFeO does not lead to the appearance of a low-spin state of Fe ions, as was predicted by some first-principles calculations. A composition dependence of the magnetic phase transition temperature for BiFe Cr O is very similar to that in the solid solutions of BiFeO with non-magnetic ions, implying the lack of magnetic exchange between Fe and Cr . The reason of such behavior seems to be a difference in their electronic configuration. Addition of Cr to PbFe Sb O leads to a dramatic lowering and diffusion of the dielectric permittivity maximum and its shift to lower temperatures. Thus, Cr substitution for Fe seems to destroy both ferroelectric and magnetic long-range order in perovskite multiferroics.