The video posted on social media Sunday, said the eight men were beheaded in the central Syrian province of Hama.
The men, wearing orange uniforms with their hands tied behind their backs, were led forward in a field by teenage boys.
They were then handed over to a group of ISIS fighters - with each fighter receiving a knife from one of the boys before beheading the men.
An ISIS fighter speaks in the video, using a derogatory term for Shiites and calling them "impure infidels."
ISIS has beheaded scores of people since capturing large parts of Iraq and Syria last year.
Today According to a local source in Nineveh province of iraq, the elements of the ISIS organization beheaded 3 people south of Mosul on Saturday.