Room temperature photoluminescence (PL) spectroscopy was done to investigate luminescent trap states in sol-gel deposited (Ba,Sr)TiO3 thin films. The pre-sintered films showed three distinct PL peaks. Increase in the peak intensity was observed with increase in pre-sintering temperature. These PL peaks were assigned to (a) singly charged oxygen vacancies (b) TiO 2 networks and (c) the contribution from the substrate. In contrast, the sintered samples showed only a band-edge luminescence with an intense peak near the band-gap energy. Identification of such observed trap states are important in understanding the results of dielectric measurements because they contribute to the leakage currents and loss mechanisms. ©2005 The Japan Society of Applied Physics.