The sentences were handed out Wednesday in northern Quang Ninh Province.
Lao national Inthavong Paseuth, 41, and Vietnamese nationals Nguyen Ba Ngoc, Lieu Van Lau, Vu Dinh Tuan and Ha Hong Quan were sentenced to death.
Vietnamese nationals Tran Huu Dinh, Nguyen Van Trang, Luong Duong Hai and Hoang Xuyen received life sentences. Hoang Duc The, Vu Dinh Hoan, Nguyen Van Hoang and Hoang Ngoc Hung received 20 years each in prison.
Two suspects in the case, Ly Van Bao and Hoang Thanh Luan, are currently on the run.
A police bust in Quang Ninh's Mong Cai Town at China border on June 16 last year found Trang, 43, hiding 23.7 kg of heroin inside a refrigerator.
Further investigations led to the arrest of 12 other members of a drug trafficking ring that had successfully transported 48.8 kg of heroin from Laos to Vietnam and then to China to be sold.
Paseuth was determined to be the provider of the drugs in Laos, said the police.
Vietnam has recently seen a rise in drug use and trafficking. Busts and convictions are reported in the country almost every week though it has very tough drug laws.
Those convicted of possessing or smuggling more than 600 grams of heroin or more than 2.5 kilograms of methamphetamine face the death penalty. The production or sale of 100 grams of heroin or 300 grams of other illegal narcotics is also punishable by death.