The best way to get from Siem Reap to the Thailand border is by taxi. It will cost around $30 to $45. An easy way to arrange for the taxi ride is through your hotel reception. Make sure that you leave Siem Reap by late morning - otherwise you may not be able to finish the trip in one day.
Your ride to Poipet should be fairly comfortable, at least compared to what it used to be. The roads have improved drastically in the last few years. The taxi ride will take about three hours.
When you get to the border, thank your taxi driver and walk along the road until you reach the customs area. Depending on the time of day, you may have to wait in line for up to two hours to get through customs.
Once you are through the border crossing and into Aranyaprathet, find a motorcycle taxi [50 baht] or a tuk-tuk [80 baht] ride to the bus station. This should be about an eight minute ride.
Buy a bus ticket to Bangkok. The last bus departs at 7pm. The ride should take somewhere between 4 and 8 hours and cost between 150 and 250 baht, depending on the type of bus. The two bus services, one government-run and the other private, are located next to each other. The fastest and most comfortable option is the government-run buses.
In Bangkok, the bus will drop you off at the Northern Bus Terminal. Take a taxi or the sky train to your hotel.
