Cambodia by Air :

It is possible to fly to the international airports in Phnom Penh or Siem Reap and get a Visa at the normal price :
- One month tourist visa for US$20 plus one or two photos
- One month business visa US$25.
International Departure tax is an hefty US$20.  Domestic Departure tax is also pricey at US$10 from Phnom Penh or US$4 from elsewhere.
More information about Cambodia Visa
 

Cambodia by Land :

The following countries offer land crossing with Cambodia :

Cambodia Thailand :
- Poipet near Aranya Prathet (Thailand) is the entry point for the adventurers (the road has been improved) who wishes to reach  Siem  Reap  and  Angkor  Wat  by road.
- Hat Lek (Thailand) near Koh Krong  is the costal entry point for those who wishes to reach Sihanoukville or Vietnam. Both offer visa facilities.

Cambodia Vietnam :
There are two legal entries points plus a much more adventurous one in the north (officially closed to foreigners). Outside of flooding, the crossing at Moc Bai remains the best bet, with buses between Phnom Penh and Saigon run by a number of guesthouses for around US$9. The new crossing at Kaam Samnor (or Vinh Xuong in Vietnamese) is a bit more tricky : you need to take a bus from Phnom Penh to Neak Long, a speedboat down the Mekong to Kaam Samnor (R10.000 per person), a moto between the immigration posts and another one to Chau Doc in Vietnam. Expect at least 5 hours. Another access possible via Kep in the south. Whatever the crossing, get your visa in advance. There is no longer the need to write the entry or exit point on the Vietnamese visa.

Cambodia Laos :
Border: Voen Kham/Dom Kralor
Your Cambodia Visa will last for 30 days.
Price: 20 US dollars