http://rubikhealth.com/en/articles/m...-into-thailand
Essential travel documents you must carry and submit to airline officials before check-in at the airport of origin are as follows:
- Foreigners:The Fit to Fly Health Certificate which has been certified or issued no more than 72 hours before travelling
- Thai Citizens:The Fit to Fly Health Certificate which has been certified or issued no more than 72 hours before travelling, and a letter from the Royal Thai Embassy