It covers most of the Peloponnese peninsula, except for the northwestern subregions of Achaea and Elis which belong to Western Greece and a small portion of the Argolid peninsula that is part of Attica.

With the 2011 Kallikratis plan, its powers and authority were redefined and extended.

Along with the Western Greece and Ionian Islands regions, it is supervised by the Decentralized Administration of Peloponnese, Western Greece and the Ionian Islands based at Patras.

[1] The Gross domestic product (GDP) of the region was 8.2 billion € in 2018, accounting for 4.5% of Greek economic output.

GDP per capita adjusted for purchasing power was 17,400 € or 57% of the EU27 average in the same year.