The geometrid genera Synopsia Hübner, 1825 and Synopsidia Djakonov, 1935 are revised, both being earlier validated at genus rank. Type specimens, original descriptions and additional specimens from different localities were examined. The revision is based on morphological characters, molecular data and distribution records. As a result, Synopsidia syn. nov. is regarded as junior synonym of the genus Synopsia. The synonymies of the species Scodonia tekkearia Christoph, 1883 and Synopsia znojkoi Djakonov, 1935 with Synopsia phasidaria phasidaria (Rogenhofer, 1873) comb. nov. are confirmed. Furthermore, Synopsidia phasidaria alvandi Wiltshire, 1966 syn. nov., Synopsidia phasidaria ardschira Brandt, 1938 syn. nov., Synopsidia phasidaria chiraza Brandt, 1938 syn. nov., Hashtaresia jodes Wehrli, 1936 syn. nov. and Synopsidia phasidaria mirabica Wehrli, 1941 syn. nov. are regarded as synonyms of Synopsia phasidaria phasidaria (Rogenhofer, 1873) comb. nov.. Synopsia phasidaria afghana (Wiltshire, 1966) comb. nov. is tentatively validated at subspecific rank. Synopsia centralis (Wiltshire, 1966) comb. nov., bona sp. is upgraded from subspecies to species level. Wing pattern, as well as male and female genitalia and diagnostic characters of examined genera and species are illustrated and analyzed. The distribution patterns of Synopsia phasidaria comb. nov. and Synopsia centralis bona sp., as well as the type localities of all discussed taxa, are provided. A complete checklist of the genus is given.