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.

That will include a new Ford Focus that charges more quickly and has a longer range, the US car giant said.
It also intends to move into the commercial ride-hailing market occupied by firms such as Uber and Lyft.
The market is worth $5 trillion, the company said.
The initiatives are part of a broader effort by chief executive Mark Fields to counter firms offering alternatives to car ownership and regulators who want vehicles to emit less carbon dioxide.
Mr Fields said the company wants 40% of its vehicles to have electric versions by 2020, up from 13% now.
The new Focus will take an 80% charge in 30 minutes, about two hours faster than the current version, Ford said. It will also have an estimated 100-mile range, as opposed to 76 miles.
The firm also plans to introduce a Mondeo hybrid and a C-Max Energi plug-in hybrid in China next year.
Ford currently sells electric, hybrid and plug-in hybrid versions of its Focus, Fusion, C-Max and Lincoln MKZ cars.
Ford also wants to expand an employee van-hailing service beyond its sprawling corporate campus, and develop it commercially.
"The market for vehicle miles travelled is $5 trillion," Mr Fields said. "We get zero of that."
Ken Washington, Ford's vice president of research, said: "Our vision is to be a mobility service provider, beyond building a vehicle that would be in somebody else's fleet. We see this as a business we want to be in."

15 March 2016 Last updated at 07:19 GMT
The Microtugs are a group of tiny robots who are being developed by a team of researchers from Stanford University in America.
The scientists who invented them tried to mimic the way that certain animals move and work together, such as ants and geckos.
On their own the Microtugs can move objects that are up to 2,000 times heavier than themselves, however the researchers decided to see if the robots could work together to pull even bigger and heavier objects.
Six of the Microtugs were able to pull a full size car - which weighed about 1800kg - meaning that together the robots were able to move more than 3,000 times their combined body weight!
Giraffes are the tallest mammals on Earth, but their numbers have dropped so low that they're now vulnerable to extinction.
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Ford says it will invest $4.5bn (Â£3bn) to expand its fleet of plug-in and hybrid electric vehicles, and will start selling 13 new electric models by 2020.
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When you think about super-strong robots, these little guys might not come to mind - but they are the Hulks of the robot world!