Hexagonal BN films have been deposited by r.f.-magnetron sputtering with simultaneous ion plating. The elastic properties of the films grown on silicon substrates under identical coating conditions have been determined by Brillouin light scattering from thermally excited surface phonons. Four of the five independent elastic constants of the deposited material are found to be c(11) = 65 GPa, c(13) = 7 GPa, c(33) = 92 GPa and c(44) = 53 GPa exhibiting an elastic anisotropy c(11)/c(33) of 0.7. The Young's modulus determined with load indentation is distinctly larger than the corresponding value taken from Brillouin light scattering. This discrepancy is attributed to the specific morphology of the material with nanocrystallites embedded in an amorphous matrix.