"We have documented the killing of 202,354 people since March 2011," observatory director Rami Abdel Rahman said, adding that more than 130,000 of them were fighters from both sides.
Abdel Rahman also emphasized that of 63,074 of the killed were civilians, including 10,377 children.
Abdel Rahman said the toll "is probably much higher than 200,000, but certain areas under the control of the regime and Islamic State group are impossible to work in freely."
He also said some 300,000 people are being held in Syria's infamous jails, including 20,000 who have gone missing entirely.
It is worth noting that there have been several attempts to refer Syria to the ICC, but Russian and Chinese vetoes at the Security Council have blocked them.