A simple and practical ultrasonically synthetic strategy for the preparation of rare-earth based catalyst, nanostructured NiFe_(2–x)Eu_xO_4 was developed. The structure of NiFe_(2–x)Eu_xO_4 was characterized by various analyses such as X-ray diffraction(XRD), scanning electron microscopy(SEM) and fourier transform infrared spectroscopy(FT-IR). The catalytic performance of NiFe_(2–x)Eu_xO_4 was evaluated for the synthesis of benzimidazoles, benzoxazoles and benzothiazoles under ultrasonic irradiation. All reactions were completed in short times and all products were obtained in good to excellent yields in presence of the rare-earth based catalyst. Besides, NiFe_(2–x)Eu_xO_4 could be recovered for 6 times without noticeably decreasing the catalytic activity. A simple and practical ultrasonically synthetic strategy for the preparation of rare-earth based catalyst, nanostructured NiFe_ (2-x) Eu_xO_4 was developed. The structure of NiFe_ (2-x) Eu_xO_4 was characterized by various analyzes such as X-ray diffraction XRD, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). The catalytic performance of NiFe 2- (2-x) Eu x O 4 was evaluated for the synthesis of benzimidazoles, benzoxazoles and benzothiazoles under ultrasonic irradiation. in short times and all products were obtained in good to excellent yields in presence of the rare-earth based catalyst. Besides, NiFe 2-x Eu x O 4 could be recovered for 6 times without noticeably decreasing the catalytic activity.