Bristol have signed Nottingham number eight Dan Montagu and Ross Johnson from Cardiff Blues for the 2009/10 season.
Hooker Johnson, 23, has made seven appearances for the Blues having come up through the ranks at the Welsh club.
Meanwhile 26-year-old Montagu, who started his career at Leicester and has also played for Doncaster, has been in fine form for Nottingham this term.
"They're two young forwards we believe have the potential to make an impact," said Bristol head coach Paul Hull.
"Ross will challenge David Blaney and Ollie Hayes for the starting hooker berth and Dan's signing gives us another big, ball-carrying back-row forward."