Does anyone know if there is a bus from Nafplio that goes directly to Athens airport? Thank you.

No, but there's an option that's just as good or better. When you buy your ticket at the Nafplio Bus station on the Athens-bound bus, ask for a ticket to ELEONAS -- that is a BLUE LINE Metro Station on the far West Fringe of Athens. (shown clearly on this Metro map -- http://www.ametro.gr/files/images/AttikoMetro_Athens_Map_eng_LG.jpg -- click to enlarge). Lots and lots of savvy passengers get off here. The driver will get your luggage from the lower compartment; just be sure it isn't buried way at the back. When you board at Nafplio, tell the driver "Getting off at Eleonas" so he'll know to put your bags right next to the compartment door.

The Metro entrance is right there ... run down the stairs, buy Metro ticket at window for AIRPORT (€8 or 14 for a ticket for 2). Be sure you "validate" the ticket by punching it in a machine enroute to the platform. Look for train with the AIRPLANE symbol on it (a few of the trains don't go all the way).

The Metro will take about 45 minutes (and you should count on a wait of 15-20 minutes or so, unless you are lucky on the schedule) ... but you will have saved a lot of time! Before I tumbled to this, I twice took the bus thru city traffic to the Kifissou st. KTEL station, THEN waited for the X93 to airport, which again encountered traffic. Much more time.

Thank you Janet. Very helpful.