Customs Department acting director general Yuthana Yimkaroon said officers found the illegal drugs in the luggage of 26-year-old Bhutanese woman, identified as Zhimo.
The detainee confessed that she was hired by an Indian man to smuggle ketamine into Thailand and was to be paid Bt20,000 once another Indian came to pick up the drugs.
The Bhutanese suspect said she has travelled to Thailand five times with a tourist visa.
Initially she will be charged with smuggling illegal drugs into the kingdom and possessing drugs for sale and distribution.
Mr Yuthana said most drug smugglers were Indians but they have turned to hire Bhutanese to do the job following a serious crackdown by Thai authorities who keep close watch on Indians.
Since October 2012 until present, Mr Yuthana said the customs department has made arrests in 298 drug-related cases, with the drugs having total street value of Bt483.5 million.