Inelastic x-ray scattering measurements of the dynamics structure factor have been performed on vitreous beryllium fluoride (v-BeF2) at T=297 K in the momentum transfer, Q, range Q=1.5-10 nm(-1). We find evidence of well defined high frequency acoustic modes. The energy position and linewidth of the excitations disperse with Q as proportional toQ and proportional toQ(2), respectively, up to about one half of the first maximum of the static structure factor. Their magnitude compares favorably with low-frequency sound velocity and absorption data. The results indicate worth mentioning similarities of the high frequency collective dynamics of different network forming glasses such as v-B2O3 and v-SiO2. (C) 2003 American Institute of Physics.