Proposals on a large number of Asian freshwater turtles and tortoises and other species popular with pet owners were accepted by the government negotiators meeting in the Thai capital.
Some of the amendments were proposed jointly by the United States and China, marking the first time these two countries have co-operated to protect reptiles.
Welfare campaigners have welcomed the move as a critical step to save these species.
Over half the world’s freshwater turtles are critically endangered. Along with tortoises, these species are much in demand by collectors and for food.
In Asia, turtles play a big part in traditional medicine as well.
The US was concerned about native turtle species, including diamondback terrapins that are increasingly under threat.
In all, 44 species of Asian freshwater turtles and tortoises and three species of North American pond turtles were upgraded in the eyes of the convention, meaning that their trade will be more carefully regulated.
“This is a huge conservation win,” the head of the US delegation, Brian Arroyo, told BBC News.
“A lot of meaningful conservation will come out of this,” he added.
The turtle vote was remarkable for the degree of co-operation exhibited by the US and China. The countries jointly submitted two proposals to increase protection for a number of Asian softshell and hardshell turtle species.
These proposals were accepted by consensus. Brian Arroyo believes the move augurs well for the future.
“This signals are that the Chinese government is committed to being serious about conservation. It’s a leap forward for both countries in terms of conservation,” he said.
Campaign groups were also pleased with the increased protection for these species.
The charity Care for the Wild said that pet owners should remember that these animals do not just come from a shop.
In a statement they said: “The trend for ‘exotic’ pets has a price, and hopefully people will start to realise that these creatures belong in the wild, not in a living room.”
– By Matt McGrath, Environment correspondent, BBC News, Bangkok