X-ray diffraction and Mössbauer studies of perovskite BiFe1−xCrxO3 and PbFe0.5−xCrxSb0.5O3 solid solution ceramics, fabricated under high pressure (4–6 GPa) have been carried out. Two morphotropic phase boundaries were revealed in the BiFe1−xCrxO3 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 Cr3+ for Fe3+ in BiFeO3 does not lead to the appearance of a low-spin state of Fe3+ ions, as was predicted by some first-principles calculations. A composition dependence of the magnetic phase transition temperature for BiFe1−xCrxO3 is very similar to that in the solid solutions of BiFeO3 with non-magnetic ions, implying the lack of magnetic exchange between Fe3+ and Cr3+. The reason of such behavior seems to be a difference in their electronic configuration. Addition of Cr to PbFe0.5Sb0.5O3 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.