The veteran South Africa lock Victor Matfield will retire as a player for the second time after this year's World Cup.
Matfield is one of six senior players leaving the Pretoria-based side, including highly-rated young loose-forward Jacques du Plessis.
Negotiations with utility back Francois Hougaard over a return for next year's Super Rugby competition are ongoing.
Matfield retired after the 2011 World Cup, but after two seasons as a coach with the Bulls he returned to the game last year.
The 38-year-old wants to coach the Bulls, possibly as early as next season, with current incumbent Frans Ludeke tipped for a different role within the union.
Loose-forwards Pierre Spies and Du Plessis will join former Springbok coach Jake White at French club Montpellier, lock Flip van der Merwe moves to Clermont-Avergne and flyhalf Jacques-Louis Potgieter is going to Lyon.
Winger Akona Ndungane, part of South Africa's World Cup-winning squad in 2007, will retire after the Super Rugby season.
The Bulls remain hopeful of retaining Hougaard, who can play scrumhalf or as a wing, but there is no deal in place yet.
"He is going to Canon in Japan, but we are still hoping to see him back here for next year's Super Rugby tournament," the Bulls High Performance Manager Xander Janse van Rensburg said in a statement.