Flanked by club president Fábio Koff, Enderson Moreira announced the decision following Sunday’s 3-2 defeat to Coritiba.
Grêmio currently sit tenth in the table but are only three points off Fluminense in third position. Nevertheless, Sunday’s defeat has prompted a change at the Gaúcho club.
"We regret today’s result. After talking with the directors, Rui [Costa, executive director], Chitolina [football coordinator] and the president, we have decided that things haven’t gone the way we had hoped," said Moreira at the post-match press conference.
"I especially regret the situation. I would publicly like to thank the fans and I apologise that things didn’t go well."
The club’s Under-20 coach André Jardine will take temporary charge of first team affairs.
Grêmio now face two consecutive away games starting with Vitória on Saturday, in Salvador, followed by a clássico against Internacional on the August 10.