Epitaxial magnesium ferrite thin films have been grown by molecular beam epitaxy (MBE) on MgO(100). Growth conditions such as substrate temperature and growth rates were optimized. By using different characterization techniques, structural, electrical and optical properties of the films were studied as a function of Mg content. In particular, we highlight the importance of the growth rate on the actual Mg/Fe ratio in the film. (C) 2016 Elsevier B.V. All rights reserved.