Thailand is one of the largest plastic polluters in the world, dumping over 1 million tons of garbage into the sea annually, according to the country's Ministry of Natural Resources and Environment.
But it suffered convulsions during the rescue attempt and vomited five plastic bags shortly before it died.
The pilot whale was found by Thailand's marine authorities struggling to swim in the Na Thap Canal, north of the Malaysian border, on Monday.
A veterinary team tried "to help stabilise its illness but finally, the whale died" Saturday afternoon, the post said.More news: Giuliani: Trump team would try to avert subpoena
An autopsy found 80 bags and other plastic items, weighing around 17 lbs lodged in the whale's stomach, which made it impossible for the mammal to eat food, marine experts said.
The report from the UK Government Office for Science found that 70% of marine litter is non-degradable plastic.
A pilot whale that died on Friday in Thailand had consumed at least 80 plastic bags, marine officials said.
He said: "It's a huge problem".More news: WWDC 2018 will be all about software: No new hardware announcements
Veterinarian Watchara Sakornwimon told Euronews she had "never seen a lot of plastic in a whale's stomach like this". Pilot whales primarily eat squid but are also known to hunt octopus, cuttlefish and small fish when squid prove elusive, the American Cetacean Society said.
Just some of the plastic bags removed from the stomach of a pilot whale that couldn't be rescued in Thailand.
"I feel sorry for the animal that didn't do anything wrong but has to bear the brunt of human actions", one Twitter user wrote in Thai.More news: Six dead or missing after Guatemala's Fuego volcano erupts