Abstract Molybdenum oxide thin films have been used in microbatteries and other ionic devices. This paper reports the preparation of MoO 3 by electron beam evaporation technique. The films were deposited onto glass substrates at temperatures in the range of 100–250°C. The films were characterized by studying their structure, electrical and optical properties. The films formed at 100°C are amorphous with conductivity of about 2.5×10 −5 Ω −1 cm −1. The absorption spectrum of MoO 3 doped with LiO 2 varies with dopant which suggests that MoO 3 is suitable for electrochromic films.The effect of deposition temperature on the optical and electrical properties of the films are discussed.