Kaziranga Divisional Forest Officer S K Seal Sarmah said patrolling forest personnel confronted a group of 5 poachers near Rangalu camp in Burapahar range.
The poachers opened fire in a bid to escape but the guards retaliated and two poachers were killed in the ensuing encounter while others managed to escape.
The forest guards recovered a .303 rifle and a gun, he said.
The bodies of the two poachers were recovered later during a search operation and sent for postmortem, he said.
Altogether 18 poachers and 21 rhinos have been killed during the year in Kaziranga National Park, Seal Sarmah added.