Phnom Penh to Siem Reap: Bus, Flight or Private Car, and Which Actually Wins

The standard advice is to fly, and it was right until recently. Both Cambodian airports have moved, and both moved further out.

Siem Reap-Angkor International (SAI) opened on 16 October 2023, about 45 kilometres east of Siem Reap - a 45 to 60 minute drive, up to 75 in the rains or at peak hour. The airport it replaced was ten minutes from town.

Techo International (KTI) opened on 9 September 2025, about 20 to 24 kilometres south of Phnom Penh, a 40 to 50 minute run. Roughly double the old one.

So the flight, which is 55 minutes in the air, now looks like this door to door: 45 minutes to KTI, an hour or more at the airport, 55 minutes flying, then an hour into Siem Reap. About four and a half hours, plus whatever buffer you personally keep.

The bus is 315 kilometres on National Road 6 and takes five and a half to six hours, and it puts you down in the middle of town at both ends. That is a gap of roughly ninety useful minutes, for several times the price and two airport experiences.

The honest conclusion: fly if your trip is five days or shorter and every hour counts. Take the road if it is not, because the ninety minutes is not worth much and the country between the two cities is most of the country.

Bus - the default, and better than its reputation. Several operators run the route with air-conditioned coaches, most with a rest stop, from roughly USD 10 to 25 depending on the operator and the seat. The fastest scheduled services do it in about five and a half hours. Book a day or two ahead in the November to February peak; outside that, the morning of is usually fine.

Sleeper bus - overnight services exist with flat berths. They save you a hotel night and cost you a night's sleep on a road that is not smooth. Most people try it once.

Minivan - faster and less comfortable, around four and a half to five hours if the driver is in a hurry, which is not always something to wish for.

Private car with driver - from about USD 90 for the route and the obvious choice for two or more people. It is also the version that turns the transfer into a day: Kampong Thom is roughly halfway and has the pre-Angkorian brick towers of Sambor Prei Kuk nearby, listed by UNESCO in 2017 and older than Angkor itself. Several operators sell exactly this, a transfer with cultural stops, and it is a much better use of the day than five hours of nothing.

Flight - Cambodia Angkor Air and others run the route several times a day, 55 minutes in the air, typically USD 70-150 one way depending on season and how far ahead you book.

Boat - there is a river and lake service in the wet season, and it is slow, expensive and uncomfortable compared with the alternatives. The good Cambodian boat journey is Siem Reap to Battambang, not this one.

If you have the days, do not treat this as a transfer at all.

Battambang is the best stop in the country that nobody makes. It is not on National Road 6 - it sits west, on National Road 5 - so it is a detour rather than a waypoint, but from Phnom Penh it is about five hours and from Battambang to Siem Reap about three, which is barely more road than the direct route. You get French shophouses on a river, the bamboo train (now running on a purpose-built track at Banan rather than the original O Dambong line, which is worth knowing before you buy the ticket), and at dusk millions of wrinkle-lipped bats pouring out of a cliff cave at Phnom Sampeau in an unbroken half-hour ribbon. The same hill holds a Khmer Rouge killing cave, and meeting that after Phnom Penh and before Siem Reap is the right order for the history.

Kampong Thom is the halfway stop on the direct route, and Sambor Prei Kuk nearby is pre-Angkorian - 7th-century brick towers standing in forest, with almost nobody there.

Kampong Cham, a couple of hours out of Phnom Penh, has the bamboo bridge to Koh Paen in the dry season, rebuilt by hand every year after the floods take it.

Our 6-day and 7-day Cambodia itineraries both put Battambang between the two cities, for exactly this reason.

Direction matters. Do Siem Reap first and Phnom Penh second if you can. You have the most energy for Angkor on the days you have just arrived, it is easier to reach the Khmer Rouge sites having already seen what Cambodia built, and it puts your last day near the nearer airport.

Fly open-jaw, into Siem Reap and out of Phnom Penh. Regional carriers price the legs separately, so it usually costs the same as a return into either, and you never repeat the 315 kilometres.

Leave in the morning whichever way you go. An afternoon departure by road means arriving after dark, and National Road 6 at night with livestock and unlit motorbikes is not the part of Cambodia to experience.

Road conditions are fine - surfaced the whole way, with the normal delays for roadworks, markets spilling into the carriageway and slow traffic. The five and a half to six hours already includes that reality; do not plan on beating it.

Book ahead in the November to February peak, a day or two for buses and longer for the better private drivers. Outside peak, same-day is usually fine.

Money on the road: US dollars everywhere, riel as change under a dollar, and small notes for rest stops. Bring clean, untorn bills - damaged ones get refused.