The United Nations' refugee agency says more than 1.5 million people have fled the conflict in Syria.
Most are in camps in neighbouring Jordan and Lebanon.
The UNHCR says the situation inside Syria has deteriorated dramatically this year.
Ten weeks ago it warned the number of Syrian refugees had passed the one million mark - now it's half as much again.
The agency's spokesperson, Dan McNorton, says the number could be much higher, as many people may not have registered.
The UN says that in addition 25% cent of Syria's population - have been displaced inside the country.