Portugal has a complicated administrative structure. The base is composed by 308 municipalities (concelho - singular, concelhos - plural), and these are divided into more than 4,000 parishes (freguesias, singular - freguesia). All these are grouped into several superior divisions, some purely administrative, some specify a given activity (i.e. tourist regions or judicial areas), others have a more technical feature, while other have historical or cultural backgrounds: Alentejo, Algarve, Beira, Douro Litoral, Estremadura, Minho, Ribatejo, and Trás-os-Montes.

The most important division, is from 1976, dividing the continental territory (Portugal continental) and the two island groups (Portugal insular), the Azores and Madeira Islands - the Autonomous regions (regiões autónomas, singular - região autónoma), the country keeps as an unitary republic.

The districts (distritos, singular - distrito), are being dismantled, but they keep as the most relevant sub-division of the mainland, serving several purposes: electoral areas or regional football championships. In 1976, the districts were dismantled in the islands.

There was made a referendum in Portugal to create administrative regional autonomies in continental Portugal, but the population refused it. The need for a better organisation lead to a newer and urbanized administrative division. Thus they are continuous territorial units made by groups of municipalities.