By Plane

Thai Airways (TG) has 3 daily flights between Bangkok and Khon Kaen.

Price (June 2007):     2805 Bt  (Economy)

                                      3805 Bt (Business)

Promotion: between 1570 and 2575 Bt. Please request the conditions at your travel agency.

THAI offers special rates for people over 60 years of age.

Transfer to Khon Kaen:The bigger hotels (Sofitel, Charoen Thani, Bussarakam, Kosa, Kaenn Inn, Roma), have their own Airport Shuttles (50 Bt), to other destinations you can use the "AVIS" Airport Shutle (70 Bt). The AVIS counter is in the Arrival area near the exits.

By Car

On Highway 2 (Friendship Highway), 450km from Bangkok and 210km from Nang Khai.
The Highway is in quite good condition, but be careful if you plan a night-trip. Construction sites are mostly not illuminated and secured, reckless and drunk/drugged drivers and truckers can make your trip to a dangerous adventure.

AVIS and Budget have a branch at Khon Kaen Airport, you can rent a one-way-car at this companies.

By Train

Trains from Bangkok leave at Hualampong and Don Muang (Airport).
Highly recommended is the night-train, leaving Hualampong at 20:45 (Airport 21:32) in a 2-person 1st class cabin.
It is possible to book a cabin for 1 person only, but SRT will charge an extra 300Bt for it.

Fare :
* 1. Class Sleeper - Cabin (2 persons) 978Bt/person, single cabin +300Bt
* 2. Class Sleeper, AC,  lower berth: 589Bt, upper berth: 519Bt
* 2. Class Sleeper, Fan, lower berth: 409Bt, upper berth: 359Bt
* 2. Clas Seat, AC: 309Bt, Fan:259Bt* 3. Class Seat, Fan: 157Bt. 

* Surcharges: Express 60 (80)Bt,  Rapid 40 (60)Bt (the higher prices on weekends)

By Bus

Ordinary buses (non-AC) between Bangkok and Khon Kaen charge approx. 150 Baht. They are only recommended for smaller and adventurous people. The small space and the chaotic way of driving is by sure not everyones taste. Besides they stop in every small village to pick up or let off passengers.
Aircon buses are around 350 to 400Bt. Nakhornchai Air (384Bt) and Chan Tours (50Bt cheaper) are my recommendations.
The trip between Bangkok and Khon Kaen takes 6.5 hours, food and drinks are included in the fare and served on bord.
Nakhornchai Air has mostly new buses with 32 seats. Stopover is in Korat (Nakhorn Ratchasima), but at nighttime it is often impossible to leave the bus for a cigarette there.
Nakhornchai Air offers Online-Booking and a 5% discount on 10 trips for members. The membership card (GoCard, 59Bt) is available at the ticket counter.
NCA leaves from Bangkok at the "Northeastern Bus Terminal", Mor Chit (Lane 15-17, Ticket Counter 17-19) and the "Nakhornchai-Air Terminal" (Sathaani Nakhornchai Air, ca. 3km from Mor Chit Terminal).
In Khon Kaen the AC-terminal is at Klang Muang Rd.

Chan Tours uses double deckers with 24 seats, only 3 seats per row. It is like flying Business class, spacious and comfortable. Stopover is in Korat and Phon.

At NCA and Chan Tours it is not allowed to drink alcohol on board, and all buses are non-smokers!

Airport Transfer

The Government Bus Company offers a  Bus Service between Suvarnabhumi Airport and Nong Khai, via Khon Kaen.

There seems to be no reliable timetable at the moment, but the most actual version you will find here (Bus 825).