Tiger bones, made into pastes, are used by herbalists in China and Vietnam to cure headaches.
Two men were arrested on Tuesday in Central Vietnam after police discovered four living tigers and hundreds of pangolins in their four-seater car.
The arrests were made in Ha Tinh province after police stopped the car following a tip by local residents, said Dang Quang Niem, deputy chief of the provincial Environmental Police Department.
Police discovered the four cubs, weighing a total of 22.5 kilograms, in cages; and 119 anteater-like pangolins, weighing 422 kilograms, in sacks, Mr. Niem said.
Ho Sy Hanh, 36, and Bui Van Muoi, 33, both from the neighbouring province of Nghe An, were arrested after failing to show permit papers to transport wild animals, the online newspaper Vietnam Net reported.
The men said they were hired to transport the animals, police said.
The animals are to be handed over to the local forest management agency for release back into the wild. Illegal trafficking in tigers, monkeys and other rare animals is widespread in Vietnam and China, where their bones and other body parts are often used in traditional medicine.
A kilogramme of pure tiger-bone paste can sell for up to 5,000 dollars on the black market. Tiger paste is used to treat ailments such as headaches.
Hunting or trading in rare animals is punishable by a prison term of up to seven years and a fine of up to 20 million dong (946.40 dollars)