Thailand's trade deficit expanded to $6.53 billion in June from $5.71 billion in May, according to data from the Ministry of Commerce on Friday.
The latest figure compared with a trade surplus of $1.29 billion in the same month last year.
Exports rose 20.8% year over year to $34.7 billion, faster than the 10.5% expansion in May. Imports increased 50.3% to $41.2 billion, also gaining speed from the 35.1% growth the previous month.