The whale vomited up five bags during the rescue attempt before it died.
Last month, the Thai government said it was considering a levy on disposable plastic shopping bags.
A pilot whale that died after ingesting rubbish has highlighted Thailand's losing battle against plastic, said conservationists who called for urgent measures to cut back on pollution that also worsens urban flooding.
A pilot whale has died off southern Thailand after swallowing 80 plastic bags, Thai marine officials say.
Each year, Thailand puts over one million pounds of garbage into the ocean, making it one of the biggest offenders on earth, along with China, Indonesia, the Philippines and Vietnam.
The whale spit out five plastic bags on Friday and later died, the Marine and Coastal Resources Department said on its website. Kenya previous year enacted the world's toughest law against plastic bags.
Photos accompanying the post showed a group of people using buoys to keep the whale afloat after it was first spotted on Monday and an umbrella to shield it from the scorching sun.
"It's a huge problem", Thon Thamrongnawasawat, a marine biologist and lecturer at Kasetsart University, said.
Veterinarian Watchara Sakornwimon told Euronews she had "never seen a lot of plastic in a whale's stomach like this".
"Because he's a whale he can travel around the world".