Backs Matt Evans and Kyle Moyle, along with hookers Rob Elloway and Tom Channon, have signed contracts for next season with the Championship club.
"It's fantastic news that these guys have re-signed for another season," said director of rugby Ian Davies.
"It is always a nervous time when players are nearing the ends of their contracts, vultures circle and suddenly you're best laid plans are destroyed."
He added: "It is envisaged that these will be the first of quite a few we will be announcing over the coming week or so."
Pirates are ninth in the Championship table, with four games left to go this season - 14 points clear of bottom club Moseley.
Cornish Pirates have agreed new deals with four members of their squad.