Its capital is Missolonghi for historical reasons, with its biggest city and economic centre at Agrinio.

The surrounding regional units take in Arta in Epirus, a narrow length bordering Karditsa of Thessaly, Evrytania to the northeast, and Phocis to the east.

The longest and main river is the Acheloos, which ends as a delta in wetlands to the southwest on a rich fertile valley.

The lowest altitude in Greece is found in west Aetolia-Acarnania at about -10 meters from the sea level.

At the highest elevations, summers are cool, and snow and cold weather dominate the winter months in the Panaitoliko.

During the Ottoman period, between the 16th century until the Greek War of Independence, the region was called Karleli and formed a province (sanjak) in the Rumelia Eyalet.

The superhighway, the Ionia Odos (Ionian Motorway) which will run centrally bypassing communities began construction in 2001 at a part between Messolonghi and the curve, this section remains to be unpaved, the rest of the highway is in plan but the opening date is not yet set.