The illegal hunting of the animal, and the destruction of where they live, are two of the reasons why.
Conservationists say their population has fallen by more than one third in the past 30 years.
It's been a shock to some of those who care for the creature.
But what makes giraffes so special? Here are five facts you might not have known...
Giraffes have strong tongues that help them to get their food - and to get it fast.
They use their tongues - like humans would use their hands - to grab food. The strength helps them chew food fast to avoid dangerous predators.
Until 2016 giraffes were considered as one species, but now they're considered as four.
They are: the reticulated giraffe, the northern giraffe, the southern giraffe and the Masai giraffe.
They may all look tall and similar, but the creatures are very different - like a polar bear is different from a brown bear.
Some of these have sub-species - where the giraffes are a little different but are still the same type of giraffe.
Just like human fingerprints, no two giraffes have the same spot pattern.
And each of the different species of giraffe have very different types of spot patterns when you look at them closely.
Giraffes spend most of their lives standing up; they even sleep standing up!
They do sometimes give their legs a rest, but all that standing is ok as their legs are very strong.
In fact scientists think that a groove in the giraffe's lower leg bone - which is much deeper than in other animals - helps keep their spindly-legs strong and allow them to support their bodyweight.
The largest giraffe relative ever to have existed is thought to have been the Sivatherium giganteum.
It's believed to have lived one million years ago in Africa and Asia and had a shorter neck and legs than giraffes of today.
Giraffes are the tallest mammals on Earth, but their numbers have dropped so low that they're now vulnerable to extinction.