Luiz Felipe Scolari has been sacked as manager of Chelsea.
Scolari, who led Brazil to win the World Cup in 2002, replaced Avram Grant as boss of the club last June.
But club officials said the team's performances - and results - were getting worse at an important time in the season.
At the moment, Chelsea are fourth in the Premier League, seven points behind leaders Manchester United.
PREMIER LEAGUE MANAGER CHANGES THIS SEASON
Luiz Felipe Scolari- Chelsea - 9 February
Tony Adams - Portsmouth - 9 February
Paul Ince - Blackburn Rovers - 16 December
Roy Keane - Sunderland - 4 December
Harry Redknapp - Portsmouth - 25 October
Juande Ramos - Tottenham - 25 October
Kevin Keegan - Newcastle - 4 September
Alan Curbishley - West Ham - 3 September
Assistant coach Ray Wilkins has been put in charge while club officials look for a new boss.
Scolari was in charge at Chelsea for 36 games, winning 20, losing five and drawing 11.
A statement on the club's website said he had brought many good things to the club, and it was "with sadness" he had been dismissed.
"Unfortunately, the results and performances of the team appeared to be deteriorating at a key time in the season," it read.
"In order to maintain a challenge for the trophies we are still competing for we felt the only option was to make the change now.
"The search for a new manager has already started and we hope to have someone in place as soon as possible."