Neodymium doped nickel ferrite nanoparticles were successfully synthesized by novel sol–gel method with the aid of nickel(II) nitrate, iron(III) nitrate, neodymium(III) nitrate and lactose without adding external surfactant. Moreover, lactose plays role as capping agent, reducing agent, and natural template in the synthesis of NiFe2−xNdxO4 nanoparticles. The as-synthesized NiFe2−xNdxO4 nanoparticles were characterized by means of several techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray microanalysis and UV–Vis diffuse reflectance spectroscopy. The magnetic properties of as-prepared NiFe2−xNdxO4 nanoparticles were also investigated with vibrating sample magnetometer. To evaluate the photocatalyst properties of nanocrystalline NiFe2−xNdxO4, the photocatalytic degradation of methyl orange under ultraviolet light irradiation was carried out.