Dărmăneşti city is located in the west side of Bacău County, in Comăneşti – Dărmăneşti Depression, in the central group of Eastern Carpathians, at the confluence of Uz and Trotuş Rivers, including its valleys. From this area a Trans-Carpathian road is opened by The Uz Pass, which connected since past times the valley of Trotuş river with the upper valley of Olt river.
- north – town Asău and Comăneşti city;
- south – town Dofteana and Covasna county;
- west – town Agăş and Harghita county;
- east – towns Poduri, Berzunţi and Dofteana
Surface: 272 square kilometres.