The first Suburban line was inaugurated on 30 July 2004, using 17 OSE Class 560 DMUs between Larissa Station (Now Athens) and the Airport.

The initial planning phase of the service provided for the use of express trains (Airport Express) from Piraeus to the Airport with intermediate stations only in Athens, Agioi Anargyroi, Neratziotissa, Kifissias and Dukisis Placentias, and with a journey time of half an hour.

[citation needed] The first section of what is now Line A1 opened on 30 July 2004: the standard gauge service ran from Athens to the Airport, using Class 560 diesel multiple units.

[6] Direct suburban railway services from Piraeus and Athens to the Airport were suspended on 6 July 2008, forcing passengers to change at Ano Liosia and (until 14 February 2009) Neratziotissa.

However, most Metro Line 3 trains start or terminate at Doukissis Plakentias, with a through service to the Airport leaving once every 36 minutes.