Thai Customs officers arrested the two at Samui international airport after they arrived here from Chennai via Singapore.
The two men, identified as Virdi Hardev Singh, 51, and Puran Singh, 41, had flown in on a Singapore International Airlines flight.
Customs officials became suspicious during the luggage X-ray. A search found a total of 12 kilos of crystal methamphetamine, known as ice, in hidden compartments of their bags.
The two men confessed it was their second trip to Thailand. The first had been to check out the smuggling route.
The two will be charged with smuggling illicit drugs into Thailand.