State television showed images of the vessel flying at low altitude and moving on water.
The vessel appeared to be a more-advanced military version of the common seaplane.
A spokesperson for the war-games currently taking place by the Revolutionary Guards navy announced that the flying boat was highly capable and had successfully carried out its mission.
The television report said that the vessel could evade sea and air radar detection because of its advanced design.
The vessel has a high speed of more than 100 knots per hour and can lift in water, the report said, adding that it could fire at targets with great accuracy while in motion.
The unnamed flying boat was designed by Irans Ministry of Defence, the report added.
