Ba0.6Sr0.4TiO3 films were grown by molecular beam epitaxy on MgO(001) and LaAlO3(001) substrates. The growth mode was determined to be two-dimensional by in-situ reflection high-energy electron diffraction. The films were structurally and dielectrically characterized ex-situ using X-ray diffraction, Rutherford backscattering spectrometry, and split cavity resonance mode dielectrometry. The structural and dielectric properties of the Ba0.6Sr0.4TiO3 film grown on MgO were determined to be inferior to the film grown on LaAlO 3, as was indicated by the broader rocking curve (0.59 deg. vs. 0.17 deg.) and higher dielectric loss (0.29 vs. 0.12).