The structural, microstructural, dielectric and ferromagnetic behavior of Co-doped TiO 2 (TC) nanoparticles have been studied. TC nanoparticles were prepared by a chemical synthesis route using polyethylene glycol as a surfactant. The polymer serves as a surfactant to encapsulate the cationic species in divided groups during the reaction that confines the size and morphology of the specimen. X-ray diffraction pattern has been used to confirm the crystalline structure (rutile or anatase) and average particle size is measured using Debye-Scherer's relation. The particle's size is also measured by transmission electron microscopy. Fourier transform infrared spectroscopy has been used to confirm the formation of Ti-O bond. X-ray photoemission spectroscopy suggests that the Ti and Co ions have the oxidation states 4+ and 2 + , respectively, present in the 2p region and confirm the presence of Ti-O-Co bonds. The variation in magnetization with Co concentration is studied. Dielectric measurements were also carried at room temperature to confirm the storage charge capability of TC semiconductor, and the nano-size effect to control the dielectric constant up to higher frequency region has been observed. The enhancement in magnetization at room temperature is also observed.