I am trying to find out more information ( or existence ) of an overnight bus that leaves Nong Khai at night and arrives directly to Suvan airport in Bangkok the next morrning. I am currently in Vientiane right now and planning my trip back to the states. My deal is that my flight would leave Bangkok around 8 am, while planes and trains will not bring me to the airport on time and do not want to spend a day in Thailand. Ideally, arriving by bus around 5-6 am at the airport would be awesome and perfect !

Any such animal exists?

Thanks in advance.

was in vientiene yesterday.

I highly doubt there is one straight to the airport, but there would be plenty of busses that would depart the evening before to arrive early the next morning.

Why not walk into any of the travel agents around the main drag there and ask for them to book a bus which gets you to BKK around 6am?

google is your friend:

The bus to Nong Khai. Bus number 825 leaves at 06:00 and 22:30 from Suvarnabhumi airport to Saraburi - Nakhon Ratchasima - Kon Kaen - Udon Thani - Nong Khai.

Now do some work to find shedule other way round....

one minute later:

I want to add some info to this thead. There is a 999 bus company running a bus between Suvarnabhumi and Udon Thani, depart from either city at 21:00 daily, for 418 baht. The bus stops at Nong Khai, Khon Kean, Nakhon Ratchasima, with fares adjusted accordingly. The entire trip takes 8 hours. The bus is a downgraded "VIP" bus, air con'ed, but no big seats. It's an alternative to the arrogant AirAsia.

Myself I would fly out of Air asia or Nokair out of Udonthani.

If your flight leaves 8am, I would not risk a bus that is scheduled to arrive at 6am. That would be tight anyway, and it might not arrive before 8am. If you do want to go by bus, I' suggest to use a service that is scheduled to arrive no later than 2am - and even then you can be met with surprises. Better to be on the safe side and spend one night in Bangkok.

Just my two-satang's worth.