The Pak Chong Police Station was alerted to the fire on the Nakhon Ratchasima-bound Mittraparp Road at 12.20am.
Two fire engines took about 40 minutes to put out the fire but by then the goods and the back of the truck had been completed destroyed.
The truck driver, Somporn Chusit, 34, said he was driving with various goods from Bangkok to deliver to a customer in Ubon Ratchathani province when a motorist, who was overtaking him, alerted him to the fire at the back of the truck.
Somporn estimated the damage at around Bt3 million.