Gloucestershire trio Steve Snell, Kadeer Ali and Rob Woodman have all left the club.
The latest set of departures follows those of seamers Steve Kirby and Gemaal Hussain, who are now both at Somerset, and Anthony Ireland, who left for Middlesex. Opening batsman William Porterfield also left, moving to Warwickshire in search of First Division Championship cricket.
Wicketkeeper Snell, 27, joined Gloucestershire in 2005 and has had to compete with Steve Adshead and latterly Jonathan Batty for the gloves. His desire to get regular first-team cricket was behind his move to leave.
"Whilst Steve Snell was an important part of the 2010 line-up, we envisage he would have very few opportunities next season," said Gloucestershire chief executive Tom Richardson.
"Knowing Steve wants to and deserves to be playing first-team cricket, we agreed that it would be in everyone's best interest if he were free to pursue his career at a new club."
Batsman Kadeer Ali also arrived at Bristol in 2005 from Worcestershire and despite his undoubted promise has endured mixed fortunes with the club. Last season he played just six first-class games making 240 runs at 21.81. He feels he can offer more having at one stage being selected for England A and hopes a new county can revive his fortunes.
"At 27 and having represented England A a few years ago, I feel I have plenty more to offer in the game and I will be looking for a new county," he said.
Former Somerset batsman Woodman, 24, was signed in 2008 but failed to establish himself and did not play a single first-team match for Gloucestershire last season.