Thailand to Vientiane: Bus, Train and Airport Options From Udon Thani, Nong Khai and Bangkok

Most people reach Vientiane from Thailand by one of four routes: the new Udon Thani airport bus, a bus or train to Nong Khai and across the Friendship Bridge, the Bangkok sleeper train, or a flight. Fares and timetables below were checked on 2026-10-26 against the sources linked in each section. Timetables change, so confirm the day before you travel.

Short answer: from Udon Thani the cheapest and simplest option on published information is BKS’s daily bus (80 baht, 09:00 from Bus Terminal 1, about 3 hours). From Nong Khai, the 08:35 or 17:25 train costs 70 to 120 baht. From Bangkok, the 21:25 sleeper arrives in Vientiane at 09:05. All routes involve Thai exit immigration, then Lao entry.

Routes at a glance

Route	Time	Fare	Source
Udon Thani Bus Terminal 1 to Vientiane, BKS daily bus	about 3 h (09:00 to about 12:00)	80 baht	Nation Thailand
Udon Thani to Nong Khai by minivan, then bridge shuttle	1.5 to 2.5 h to the bridge area	150 to 200 baht minivan	Fun Bar Udon, May 2026
Nong Khai to Thanaleng by train	30 min (08:35 or 17:25)	70 or 120 baht	thailandtrains.com
Nong Khai bus station to Vientiane, Naluang bus	about 1.5 h	189 baht, 10:00 and 18:00	thailandtrains.com
Bangkok to Vientiane, sleeper train 133	21:25 to 09:05	574 baht (2nd class sleeper), 281 baht (3rd class seat)	Seat61, June 2026

From Udon Thani: the new BKS airport bus

BKS launched a daily bus on 9 September 2026 linking Udon Thani, Udon Thani International Airport and Vientiane on Route No. 2, an 87 km route using 40-seat air-conditioned buses, Nation Thailand reports. The fare is 80 baht.

• Outbound: departs Udon Thani Bus Terminal 1 at 09:00, stops at the airport at 09:30, reaches Vientiane about noon.
• Return: departs Vientiane at 14:00, reaches the airport at 16:30 and the Udon Thani terminal at 17:00.
• Booking: BKS website and E-Ticket app, LINE @BKS99, BKS counters, or the Udon Thani bus station on 080-079-7315.

It runs once a day in each direction, so it suits a morning flight arrival best. If you miss it, the Nong Khai options below still work. Whether the bus completes both border formalities on board is not described in the report, so budget time at the border.

Via Nong Khai: train and bridge shuttle

Udon Thani sits about 55 km south of the First Thai–Lao Friendship Bridge. The standard overland route is a local bus or minivan to Nong Khai (a May 2026 guide quotes 100 to 150 baht for the local bus (about an hour, plus a tuk-tuk to the bridge) and 150 to 200 baht for a minivan (1.5 to 2.5 hours), minivans leaving every 30 to 60 minutes from about 06:00 to 18:00), then either:

1. The train from Nong Khai to Thanaleng, just across the river. Two trains daily at 08:35 and 17:25, 30 minutes, 70 baht in 3rd class or 120 baht in 2nd at the station (170 and 120 baht booked online). Thai exit and Lao entry formalities apply as on any land crossing.
2. The bridge shuttle from Nong Khai bus station. You can’t walk across; the shuttle runs about every 20 minutes and costs about 20 to 30 baht (thailandtrains.com, Seat61). On the Lao side, thailandtrains.com lists a green bus to Vientiane Central Station for 8,000 kip or a minivan for about 400 baht.

Visa-on-arrival is quoted at US$35 (or 1,500 baht) by thailandtrains.com and US$40 by Seat61, and Seat61 says e-visas have been accepted at Vientiane since February 2025. Fees depend on nationality, so check the official Lao e-visa portal before you go. If you booked through a tour operator, see our note on the May 2026 hotel-booking proof rule, which applies to operators.

From Bangkok: sleeper train or flight

Train 133 leaves Bangkok at 21:25 and arrives in Vientiane at 09:05, with about 40 minutes at Nong Khai while Thai exit checks are done, according to Seat61 (updated 2026-06-06). Seat61 lists the 2nd class air-conditioned sleeper at 574 baht and a 3rd class seat at 281 baht. Direct flights also run from Bangkok to Vientiane, which saves the night but costs more; check current fares, as we haven’t verified a price for this guide.

Your phone on the way

Laos eSIMs are data only, so you can buy ahead. Install the eSIM on the Thai side, where you have Wi-Fi, and keep your Thai SIM for calls. Check the activation rules for your plan in the activation guide before you switch data to the Laos line. Our Thailand to Laos eSIM guide covers the switch step by step, and the Laos eSIM plans list data sizes and prices. If your trip continues into Vietnam, see Hanoi to Vientiane for the other direction.

Onward from Vientiane

Heading north to Luang Prabang next? See Vientiane to Luang Prabang: train, bus or flight.

Written by the Internet in Laos team. Fares and times checked against the linked sources on 2026-10-26; we have not ridden every route this month, so treat times as published rather than observed.