Tigers are being forced to live in small areas which are shrinking still further, the largest ever study of habitat for the species has revealed.
Poaching for skins is a major cause of decline for tigers
They have lost 40% of their habitat over the last decade, and now occupy only 7% of their original range.
The study, by a number of conservation groups, identified 76 places that are safe for tigers to live and breed.
The groups urge leaders of the 13 states where tigers live to convene a summit on protecting remaining habitat.
"This report documents a low-water mark for tigers, and charts a way forward to reverse the tide," said John Robinson of the US-based Wildlife Conservation Society.
"We can save tigers forever."
A century ago, there were approximately 100,000 tigers in the world; now numbers are down to only 5,000.
The principal cause for their decline is human use of what was once tiger habitat, though there is also hunting for skin and other body parts.
Scientists have now conducted an extensive survey to locate the best areas for supporting wild populations in the future.
They rated the areas by various criteria including the extent of human influence and apparent tiger numbers.
The group identified 76 areas which could in principle support wild populations; half could support 100 or more animals.
The greatest potential lies in India and the Russian Far East, though many areas in South East Asia could also sustain healthy populations.
One of the conservation groups involved, WWF, said it is ready to support the 13 countries where tigers currently live.
But working out ways to use these viable habitats is not just a matter for individual governments, said Eric Dinerstein, chief scientist at WWF-US.
"As tiger range spans borders, so must tiger conservation," he said.
"Asia's economic growth must not come at the expense of tiger habitat and the natural capital it protects."
WWF urges the 13 head of states to convene a special summit to raise the issue on their governments' agendas.
The tiger (Panthera tigris) is the largest cat on the planet, and contains several varieties including the Siberian, Sumatran and Bengal tigers.
Controlling poaching can slow the decline in tiger numbers
Sub-species such as the Javan, Bali and Caspian tigers are already extinct, and the species overall is categorised as Endangered according to the internationally recognised Red List.
They live for between eight and 10 years in the wild and grow to nearly three metres [nine feet] in length, eating a varied diet including fish, birds, reptiles and mammals.
But habitat is crucial. A female tiger occupies between 25 and 1,600 square kilometres [10 and 625 square miles], while males range over even larger areas.
As forest, grassland and swamp margins disappear, so do tigers.
In some areas, conservation efforts have paid off, with habitat protection and poaching enforcement slowing decline.
In the new report, scientists urge authorities to restrain the demand for skin or other parts of tigers and other big cats.
They also urge concrete law enforcement in illegal trade and transport.