[3] The traditional name of the region, 'Orluli', is still used today by Lian Nain [de] during ceremonies, such as the sergala, to greet important guests.

The municipality borders Aileu to the north, Manufahi to the south, Cova Lima to the southwest, Bobonaro to the west, and Ermera to the northwest.

Ainaro played an important role during the brutal Indonesian occupation of East Timor, providing shelter for the mountain-based guerrilla resistance army.

Former guerrilla leader, former President, and current Prime Minister Xanana Gusmão spent many years directing the resistance from Ainaro.

The municipality's administrative posts (formerly sub-districts) are:[5] 62.4 % of the population speaks Mambai as mother tongue, 29.1 % Tetum and 7.5 % Bunak.