ABSTRACT. Nanoparticles of CuS, TiO2 and CuS/TiO2 composites were prepared by template free hydrothermal method. Prepared nanoparticles were characterized by X-ray diffraction (XRD) and electron dispersive X-ray spectroscopy to confirm the formation of nanoparticles. Field emission scanning electron microscopy (FESEM) was applied to investigate the morphology and particle size of the nanoparticles which were measured in the range of 30–40 nm. Photocatalytic performance of CuS, TiO2 and Cus/TiO2 were measured by degradation of methyl orange (MO) under solar light irradiation. Coupling of n-type TiO2 (3.2 eV) with p-type CuS (1.9 eV) showed efficient degradation of the contaminants under the solar light irradiation. Photocatalytic performance of CuS/TiO2 composite improves 1.4 times than CuS for the degradation of methyl orange (MO) under solar light irradiation. KEY WORDS: CuS/TiO2 composites, Photocatalytic performance, Hydrothermal growth, Solar light, Irradiation Bull. Chem. Soc. Ethiop. 2019, 33(3), 561-571. DOI: https://dx.doi.org/10.4314/bcse.v33i3.1