Of the four published osmium fluorine compounds in the oxidation state +7, OsO3F, OsO2F3, OsOF5, and OsF7, only one (OsOF5) is a real Os(VII) compound. OsO3F has obviously been OsO4. OsO2F3 in its two modifications is a mixed-valence Os(VI)/Os(VIII) compound, whereas a new compound Os2O3F7 is a mixed-valence OsV/Os( VIII) compound. The molecular structures of OsO3F, OsO2F3, and OsO3F2 are calculated. OsO3F2 seems to exist in two forms, with D(3)h and C-s symmetry. The original preparation of OsF7 could not be reproduced, only OsF6 has been obtained.