Barium titanate (BaTiO3) thin films have been deposited on single‐crystal magnesia (MgO) substrates by pulsed‐laser ablation. Temperature dependence of capacitance measurements show a peak of 110°C, indicative that a ferroelectric phase transition has occurred at this temperature. This value is lower than that determined for single‐crystal BaTiO3, but consistent with that found for BaTiO3thin films produced by other methods. It has been demonstrated that the microstructure of the films can be varied by changes in the deposition parameters. Optimizing these variations permits the formation of thin films with controlled microstructures and prop