When choosing between flights to Laos, you should take into account not only price but also, depending on how much time you have, which parts of the country that you wish to see.
While flights into the capital of Vientiane will undoubtedly be cheaper, you'll be faced with a long, overland bus journey on mountainous roads to visit Luang Prabang in the north or Si Phan Don (The 4000 Islands) in the south.
Route 13 Through Laos
Although the primary north-south highway through Laos has improved over the years, many travelers would agree that '13' is an appropriate number for the notorious road. While taking the narrow, mountainous connector between Vientiane, Vang Vieng, and Luang Prabang provides you with beautiful scenery and a chance to at least pass through small villages, the journey can be a hair-raising experience.
The freedom fighters who once robbed buses are gone, but Route 13 is still plagued with speeding buses and reckless drivers careening around sharp switchbacks; wrecks are not uncommon. Some locals and travelers even refuse to travel the highway by bus and instead opt for cheap flights between Vientiane and Luang Prabang.
Flights to Vientiane
Flying into the capital of Laos is certainly the easiest if not the cheapest choice for getting into the country. Wattay International Airport (airport code: VTE) is conveniently located only two miles outside of the city and handles the largest number of flights into Laos.
The airport in Vientiane receives flights from Kuala Lumpur (Malaysia), Bangkok, China, South Korea, Vietnam, Cambodia, Singapore, and other points in Laos. AirAsia -- the premier budget airline in Asia -- operates cheap flights from Bangkok and Kuala Lumpur.
Beginning your trip in Vientiane is the most logical of entry points, however, you'll have to grab a quick flight or take a long bus along Route 13 to see Luang Prabang.
Flights to Luang Prabang
If the primary purpose of your visit to Laos is to see Luang Prabang -- the famed cultural capital on the Mekong River -- you may wish to consider flying into the small airport there.
Luang Prabang International Airport (airport code: LPQ) was once considered a relatively dangerous place to land due to the approach through mountainous terrain. The small airport has undergone numerous expansions and runway extensions. You can fly directly into Luang Prabang from Thailand, Hanoi (Vietnam), Siem Reap (Cambodia), Yunnan (China), and other parts of Laos.
If you plan to take advantage of the great trekking in Luang Namtha, you'll want to fly into Luang Prabang and take the bus north.
Vang Vieng Airport
Ironically, Vang Vieng is actually built on an old top-secret CIA airstrip once used for covert missions during the Vietnam War, but there is no airport nearby. To visit Vang Vieng, you'll need to fly into Vientiane then take one of the many minivans or tourist buses that go north.
Flights to Si Phan Don
If you want to take in the backpacker vibe and see the pink dolphins among Laos' river islands (the 4000 Islands), you'll be better off flying into Pakse International Airport (airport code: PKZ) in the south of the country. The tiny airfield is used by the military but also handles flights from Bangkok, Ho Chi Minh City, and Da Nang in Vietnam, Siem Reap in Cambodia, and other places in Laos.
Getting to Phonsavan
To see the ancient Plain of Jars near Phonsavan, you'll probably have to get there by bus. While the tiny airstrip in Phonsavan (airport code: XKH) has a handful of flights from Vientiane per week, schedules are irregular and flights are often canceled.
You can reach Phonsavan via bus from Vientiane or Luang Prabang, however, Luang Prabang is closer to seeing the Plain of Jars.
Getting to Laos from Thailand
While there are plenty of budget flights available from Bangkok to Vientiane, Luang Prabang, and even Pakse, you can also go overland -- by bus or boat -- from Thailand. If time isn't an issue and you're departing from Pai, Chiang Mai, or Chiang Rai in the north of Thailand, getting to Luang Prabang by boat can be a unique experience with incredible Mekong scenery to enjoy.