We visited Cambodia in October 2013. On the way in, we flew from Bangkok to Siem Reap.
Cambodia provides visa on arrival to Indians and most other nationalities. You need to pay $20 on arrival to get a visa that is valid for 3 months and allows 30 days of stay within the country.
Beware that if you are entering Cambodia by bus from Thailand, sometimes there are agents that will try to rip you off. They will make up any story to get your money off you. In this case, it’s always better to get an e-Visa from Cambodia beforehand. You can apply for an e-Visa directly with the Cambodian government. It costs $5 extra (so a total of $25) but you will have a legit visa that can me used at many Cambodian border crossings without issues. The whole process takes 2-3 business days so make sure you apply in advance. If you didn’t manage to apply, you can still get visa on arrival at the Cambodian border but be sure to dodge any agents that come after you!
After landing at Siem Reap's airport
The visa process on arrival at Siem Reap airport is pretty straightforward. There is *no* ATM in the arrivals hall so if you aren’t carrying USD 20 for your visa application, you will be escorted outside to use an ATM but this will cause delays. It’s best to carry some USD with you when you arrive at the airport.
Upon arrival, we stood in line and filled the visa application form. It required one photograph and some details about our stay in Cambodia (hotel address, etc.).
Then, we waited in line to reach the visa counter. The visa officer accepted our application, stapled the photograph to our form, took our money, and asked us to wait for our turn. The passport and visa application move through several counters and eventually the folks at the last counter will call out your name.
The entire process took about 20 minutes. They called out our name and we collected our passports.
Pretty simple!