A tip-off led to the two vehicles being stopped near Takuapa in Phang Nga province about 4pm. Authorities believe the group was being trafficked.
The two Thai drivers, Chawang Songsan and Suriya Yotrak, both 34, were arrested.
Officials were told the vehicles were heading from Ranong on Thailand's border with Burma to Sadao, on the border with Malaysia
Thirty-three men were taken to the council offices in Takuapa overnight and were due to be passed to police and Immigration in Phang Nga Town today.
Three women and a boy were taken to the government-run family shelter in Khao Lak.
Although there was no translator involved, officials believe the group were Rohingya fleeing ethnic cleansing in Burma (Myanmar).