The densities of methyl fluoride were reported at T= (298.15 to 573.15) K and at p = (10 to 300) Wa. Experiments were performed with a thin-valled sample holder which was under equal pressure, both inside and outside. The volume change of the sample was determined with a separation system at T= 298.15 K by making use of a float on mercury and a linear variable differential transformer. The density of methyl fluoride varies in this region p = (2.218 to 29.602) mol.dm(-3). The uncertainty of data for densities was estimated to be better than +/-0.37%. The experimental data are described by the Tait equation. (c) 2007 Elsevier Ltd. All rights reserved.