A series of polycrystalline nanoferrite having the chemical formula CoCrxFe2−xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by sol-gel autocombustion method. X-ray diffraction (XRD) analysis was used to investigate the structural parameters and also to check the phase purity of all prepared samples. The analysis of XRD patterns revealed the formation of single-phase cubic spinel structure for all samples. The average particle size of the synthesized ferrites was identified by X-ray diffraction and scanning electron microscopy technique. The magnetic properties of Co-Cr nanoferrites were measured using a hysteresis loop tracer at room temperature and magnetic field of 5 KOe. Saturation magnetization (Ms) and coercivity (Hc) decrease with the increasing Cr3+ ions concentration in the Co-Cr ferrite, indicating that lesser magnetic Cr3+ ions substitute Fe3+ ions in the octahedral sublattice of the ferrite. Such materials are useful to reduce the energy loss in AC electrical appliances.