It comprises the eastern half of the island of Timor, the nearby islands of Atauro and Jaco, and Oecussi-Ambeno, an exclave on the northwestern side of the island, within Indonesian West Timor.
It takes up the east side of the island of Timor, the islands of Atauro and Jaco as well as Oecussi-Ambeno on the northwest side, surrounded by Indonesian West Timor.