The five tigers were discovered in the central province of Nghe An on Monday.
Tiger organs and bones are used for medicinal purposes in the communist country, where a thriving local market drives the illegal sale of animal parts including ivory and rhino horn.
But Vietnam is also a key transit route for wildlife parts destined for elsewhere in Asia, including neighbouring China.
The five tigers were discovered in the central province of Nghe An on Monday, according to a report from the official provincial newspaper.
"The authorities found inside a freezer five dead tigers, with the skins intact but the internal organs removed," it said.
The tigers were Indochinese, according to Vietnam News Agency, but officials said police would investigate further.
Police refused to comment.
Tiger bones are commonly boiled down and mixed with rice wine in Vietnam, a mixture believed to treat arthritis and promote strength.
Conservationists say Vietnam is one of the world's worst countries for trade in endangered species, an accusation which it denies.
Police regularly seize hauls of ivory, rhino horn and exotic species including pangolins, but conservation groups say these represent just a small part of the trade passing through the communist country.
Britain's Prince William delivered an urgent plea in Vietnam in November to end wildlife trafficking to save critically endangered species.