One in five of the world's mammals, birds, fish, reptiles and amphibians are under threat of dying out, according to a new study.
Scientists checked the status of more than 25,000 species on the Red List of Threatened Species and found the number of creatures under threat is going up.
On average, 52 species are moving closer to extinction every year.
But it's not all bad news. Some endangered animals are making a comeback thanks to conservation work.
White rhinos are among the species said to have benefited from conservation
The white rhino and humpback whale are just two of 64 species that are said to have benefited from work to protect them and their habitats.
Others may not have seen their numbers go up, but scientists say without conservation they would be a lot worse off.
The report has been released as governments from around the world are meeting to try to find ways to protect the natural world.