One man is shown kneeling blindfolded in front of a group of men who hurl large stones at him until he is lying face down on the ground, blood running from his head.
A second man is then killed in the same way, as a crowd including children looks on.
It is not known when the stonings took place, and the authenticity of the pictures could not be immediately confirmed.
IS has carried out a string of atrocities including videotaped beheadings and mass executions, rape and enslavement in areas it controls in Iraq and neighbouring Syria.