Your two best options to get to Pattaya from the Bangkok Airport are either by taxi or bus. I recommend taking the bus because it is less than 10 percent of the cost of a taxi, but the buses only run during daytime hours and you may have to wait an hour or two before it leaves.
To catch the bus to Pattaya, go down to the bottom floor of the airport where the bus terminal is located. The bus schedule is posted on the counter, and you will need to purchase your ticket ahead of time as the seats sell out fast, especially in high season and on weekends. The last time I took this bus route the price was only 120 baht, but that was over three years ago, mind you.
If you are in a hurry, or if you take the redeye flight which arise after the buses have stopped running, you will need to take a taxi to Pattaya. There are always plenty of taxis standing by, but it will cost you about 1500 baht for the trip.If you have a friend or two to split the cost with than this may be a good option for you.Tip: You can save money if you pre-arrange and prepay ahead of time for the taxi driver to meet you at the gate.
It only takes about 90 minutes of driving time to get to Pattaya, as the trip is only approximately hundred kilometers. Bangkok and Pattaya are connected by surprisingly modern highways that make for easy travel.