There has been a boom in international routes into the city ever since Luang Prabang International Airport got a smart new building and an expanded runway in 2013. Bangkok Airways (www.bangkokair.com) and Air Asia (www.airasia.com) both fly daily to Bangkok, while the latter also serves Kuala Lumpur. Lao Airlines serves Vientiane several times daily, as well as Pakse, Chiang Mai and Hanoi once daily. It also has frequent flights to Jinghong and Chengdu in China. Vietnam Airlines flies to both Siem Reap (codeshare with Lao Airlines) and Hanoi daily; buy tickets through All Lao Travel.
Taxi-vans at the airport charge a standardised 50,000K into the city centre (4km away). These will cost more if more than three people share the ride. From town back to the airport you might pay marginally less.