The tanker MT Orkim Harmony was carrying around 6,000 tonnes of petrol worth an estimated USD 5.6 million when it was commandeered by the eight men on June 11 last year.
The tanker was en route from Malaysia's western coast to the port of Kuantan on the east coast.
Six of the pirates were sentenced to 15 years in jail and five strokes of the cane, while the other two were handed 18-year jail sentences, a Malaysian Maritime Enforcement Agency official told AFP.
He said that the Indonesians pleaded guilty after they were charged yesterday in the southern state of Johor, neighbouring Singapore.
Noel Choong, head of the International Maritime Bureau's Kuala Lumpur-based Piracy Reporting Center, said the shipping community hailed the punishment.
"We welcome the tough punishment. It will send a strong signal to potential pirates that crime does not pay," he told AFP.
The eight suspects had eluded security forces by escaping from the tanker on a lifeboat under cover of darkness, Malaysian authorities said at the time, after warships were scrambled to hunt down the men.
The tanker's 22 crew members were mostly unscathed except for an Indonesian sailor who was treated for a gunshot wound to the thigh.
The hijackers subsequently washed up on Vietnam's southwestern Tho Chu island on a lifeboat claiming to have had an accident at sea about a week after the hijack.
But they were taken into custody after local officials discovered they were carrying large sums of cash, and were accused of hijacking the MT Orkim Harmony oil tanker.
The Indonesians pirates were extradited to Malaysia early yesterday after being held by Vietnamese authorities for almost 18 months.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)