If you consider flying from Bangkok to get close to Khao Sok National Park, please note that there are three possible airports: Surathani, Phuket and Krabi.
Surathani Airport is the closests in distance; Phuket Airport will have the most options and offers as it is the biggest; and Krabi Airport is at the same distance as Phuket, yet getting to Khao Sok Park via public transportation is complicated.
Click the following links to find out how to get from the airports to Khao Sok Park:
BANGKOK TO KHAO SOK BY TRAIN
From Bangkok, take the 2nd class sleeper train, which is air-conditioned, comfortable and at approx. 800 baht one-way (a very good deal). There are several trains every night, but the 7 PM train arrives at Surathani at about 6 AM. However, as with any form of transportation, it can sometimes be delayed.
Click here for a timetable of trains.
From Bangkok check the timetable for Southern Line
From the Surathani train station, you can get a bus to Khao Sok. Exit the front entrance of the train station and 30 meters to the right take the Surathani-Phuket bus.
For more information about transport to Our Jungle House from Surathani click here.
BANGKOK TO KHAO SOK BY NIGHT BUS
At the bus stations in Bangkok you can find buses that head south to Surathani. The Southern Bus Terminal (Sai Tai Mai) has buses that travel to the southern provinces, and is located at Phutthamonthon Soi 1 in Bang Ramat, Taling Chan, northern Thonburi. You may call them under 0 2434 5557-8 or drop a visit to find information on their timetable. Have a look here for directions of what to do once you make it to Surathani.