Three cases of bullets were unearthed on Friday in Kandal province when an excavator dug land to build a pagoda.
The bullets were collected to be kept in a police station.
Pa Sam Ith, the local police chief, said the bullets were too old to represent a serious danger.
They will be given to Cambodia Mine Action Centre, he said.
Mr Sam Ith said authorities often tell villagers to be careful with unexploded ordnances, and to report any to police.
Meanwhile, nine unexploded 122mm rockets were recently found in Battambang.
Police officials said the rockets would be given to CMAC to dispose of.