The structural and magnetic characteristics of Li0.4Zn0.2CrxFe2.4-xO4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) ferrites produced via citrate auto-combustion were investigated. Various intriguing modifications in the values of structural factors such as lattice constant, crystallite size, and X-ray density have been detected as the Cr3+ concentration is raised. X-ray diffraction validated the cubic spinel structure's single phase. The lattice parameter drops as the chromium concentration rises. The wide lines suggest that the particles are nano-sized, and the crystallite size (t) was determined to be between 23 and 27 nm. The estimated crystallite size from Williamson–Hall formula decreased with Cr concentration until x=0.4 and then rises at x=0.5. After annealing the samples at 1000 oC, several magnetic characteristics were tested at ambient temperature. The magnetization M was recorded in the magnetic field up to 5500 Am-1. In addition, the influence of the applied magnetic field on relative permeability (μr) was discussed.