Mixed metal oxides possessing spinel structure exhibit interesting structural, electrical, magnetic and catalytic properties. During the course of investigation, chromium substituted magnesium ferrites were synthesized by co-precipitation technique using NaOH at a pH of 9.5. Formation of spinel phase was identified using X-ray diffraction technique (CuK alpha 1.54056 angstrom). All the compounds exhibited cubic spinel symmetry and lattice constant varied between 8.40 and 8.33 angstrom. They showed decreasing trend with increase in concentration of chromium. Infra-red spectral studies showed two strong bands one around 600cm(-1) which is attributed to the intrinsic vibrations of tetrahedral complexes and other at 400cm(-1) is due to octahedral one. The morphology and size of the particles was found by scanning electron microscope while element compositions by elemental dispersive X-ray spectroscopy. The various compounds of the system MgFe2-xCrxO4 were also investigated for their thermal, electronic and magnetic hysteresis studies. (C) 2008 Elsevier B.V. All rights reserved.