The taxonomy of several Ancylosis species is revised. Four new synonyms are established: Ancylosis brunneonervella Roesler, 1970 syn. nov. of Ancylosis albicosta (Staudinger, 1870); Ancylosis psammicola (Roesler, 1970) syn. nov. of Ancylosis leucocephala (Staudinger, 1879); Ancylosis unicolorella (Roesler, 1970) syn. nov. of Ancylosis pallida (Staudinger, 1870). The following taxa are re-instated as separate species: Ancylosis delicatella (Möschler, 1860) spec. rev., stat. nov. and Ancylosis ciliatella (Zeller, 1872) spec. rev., stat. nov. are taken out from synonymy with Ancylosis rhodochrella (Herrich-Schäffer, 1852); Ancylosis deliciosella (Caradja, 1910) spec. rev., stat. nov. is taken out from synonymy with Ancylosis hellenica (Staudinger, 1870); Ancylosis macedonica (Schawerda, 1937) spec. rev., stat. nov. is taken out from synonymy with Ancylosis muliebris (Meyrick, 1937). Heterographis costalbella Amsel, 1954—the junior homonym of Heterographis costalbella Mabille, 1906, is taken out from synonymy with Ancylosis syrtella (Ragonot, 1887) and re-instated as separate species under replacement name Ancylosis amseli Yepishin, 2020 nom. nov. Ancylosis ciliella (Amsel, 1961) syn. nov. is transferred from synonymy with A. rhodochrella to synonymy with A. delicatella. Female genitalia of A. amseli and A. delicatella as well as male genitalia of A. deliciosella and genitalia of both sexes of A. ciliatella are described for the first time. Ancylosis deliciosella is recorded as new for Iran, A. delicatella—for Azerbaijan and Kazakhstan, Ancylosis rhodochrella (Herrich-Schäffer, 1852)—for Georgia, Ancylosis larissae Bidzilya, Budashkin & Yepishin, 2019—for Russia, Kazakhstan, Iran, Afghanistan, Mongolia and China, and Ancylosis yerburii (Butler, 1884) is new for Russia and Kazakhstan.