Our high pressure x-ray diffraction studies on BiMn_1.5Ti_0.5O₅ show iso-structural phase transition above 12 GPa similar to the one observed in undoped BiMn₂O₅; however anisotropic compressional behavior is found to be more enhanced in the doped case. Unlike undoped system, an anomalous lattice expansion along caxis has been observed in BiMn _1.5Ti_0.5O₅ above 12 GPa; whereas the b lattice parameter has been found to be more compressible as compared to BiMn₂O₅ . As doping with Ti reduces the magnetic interaction ns among Mn ions, the observed changes are suggestive of having adverse magnetic implications in the observed iso-structural phase transition