[1] It connects Antirrio, at the north end of the Rio-Antirrio bridge, with Ioannina in northwestern Greece, passing through Agrinio and Arta.

The northern part, between Ioannina and Amfilochia, forms the European route E951.

tunnel (Kleisoura tunnel) which opened in 1969 The EO5 is officially defined as a north-south route through western Greece, running between Rio to the south and Ioannina to the north, via Antirrio, Missolonghi, Agrinio, Amfilochia, Arta and Filippiada.

[2] The EO5 forms part of the European route E951 from Missolonghi to an A5 motorway (Ionia Odos) interchange at Kouvaras [el], where it meets the E55, and the E952 from Agrinio to said interchange: the E951 runs via Agrinio, while the E55 now bypasses the town via the A5 motorway.

[3] Ministerial Decision G25871 of 9 July 1963 created the EO5 from the old EO18, which existed by royal decree from 1955–1963, and also followed the same route as the current EO5.