All arriving passengers are required to complete the Passenger Arrival Document no. 6 issued by the Immigration Bureau for contacting passengers during their stay in Thailand. The Passenger Arrival Document is distributed by the airline staff of the arriving flights and need to be completed before landing in Thailand.
Visas and Travel Documents for Arriving Passengers
Passengers with no visa (Please see the list of countries below) can apply for a visa at the arrival counter. You are required to bring two one-inch photographs and a 300 Baht fee for application. If you do not have photographs with you, a photo express service is available at the airport for 120 Baht (for 4 photographs).
( Information Source : Immigration Bureau )