Nanoparticle of Bi5Nb3O15 doped with Y3+ was prepared for the first time by the sol-gel method combined with impregnation. The degradation of Ornidazole reacting with Y3+-Bi5Nb3O15 was investigated to explore the feasibility of using Y3+-Bi5Nb3O15 to treat antibiotics in wastewater. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV-vis diffuse reflectance spectrum and X-ray photoelectron spectroscopy. The results showed that the Y3+-Bi5Nb3O15 exhibited single-crystalline orthorhombic structure with small particle size (20-100 nm); additionally, its UV-vis absorbance edges significantly shift to the visible-light region. The as-prepared nanoparticles exhibited a high photocatalytic activity in the decomposition of Ornidazole and several possible pathways of degradation of Ornidazole were proposed according to the results of ultra-performance liquid chromatography tandem mass spectrometry. (C) 2012 Elsevier B.V. All rights reserved.