Effect of Zn addition in Mg0.7-xZnxNi0.3Fe2O4 (with x = 0.0-0.7) prepared via solution combustion technique have been studied in terms of structural, magnetic properties, cationic distribution and surface morphology. X-ray diffraction (XRD) (with crystallite size (D) < 42.89 nm) and Fourier transmission infrared (FTIR) measurements validate the formation of spinel ferrite phase. Cationic distribution of Mg-Ni-Zn ferrite has been estimated by analyzing the X-ray intensity of the (220), (400), (440) and (422) reflections. The FTIR study between 375 and 1000 cm(-1) exhibit two absorption bands corresponding to tetrahedral (541-562 cm(-1)) and octahedral sites (423-430 cm(-1)) of Mg0.7-xNi0.3ZnxFe2O4 spinel structure. A new approach in solid state chemistry for explaining the surface active centers for Mg0.7-xNi0.3ZnxFe2O4 system is also discussed for the first time. Coercivity (H-c) decreases linearly with Zn content. Saturation magnetization (M-s) increases for lower Zn content (0.00 <= x <= 0.3) and reduces for higher Zn content (0.3 < x <= 0.7), ascribed to the distribution of cations at A, B site.