All Foreign Visitors are now able to obtain the Cambodia visa upon arrival at the airport.  It is no longer necessary to get the visa stamp at the Cambodian Embassy before your visit. Just prepare the following documents:
            + Your original Passport
            + 1 photo (3 x 4 cm)
            + US$ 25 Cash for tourist visa fee (Paid directly to the Immigration)

The Cambodia Visa is issued officially at the following ports of entry:

By Air
            Pochentong Airport in Phnompenh
            Siemreap Airport (Angkor Wat Region)

Check the airfares and flight schedules here.

By Land

Travelers can travel to/from Cambodia by land through Aranyapathet-Poipet Border and Trat-Koh Kong Border of Thailand and Moc Bai - Bavet Border of Vietnam

Cambodia Visa Validity:  30 days from the date of issue, *NOT* from the date of entry.

Visa Extension
Travelers who would like to prolong their stay in Cambodia may extend their visa at the Department of Immigration situated just opposite the Pochentong Airport. The visa may be extended for 30 days at the cost of USD 35
Some travelers have reported that the visa extension for another one month was no longer possible, since the middle of June 2000. If you expect to stay more than a month, better get a Business visa at one shot for USD 35 with three months validity.