Glenn Roeder has had his contract terminated with immediate effect by West Ham.
Roeder, who underwent surgery last season on a brain tumour, returned to work at Upton Park in the summer following the club's relegation from the Premiership.
West Ham started the season with a win at Preston but defeat on Saturday at Rotherham has been followed by him receiving the sack.
Trevor Brooking will take over as caretaker boss.
A statement on the Hammers' official website read: "West Ham United wish to announce that Glenn Roeder's contract has been terminated with immediate effect and he has been relieved of his duties as team manager.
"The Board would like to place on record their gratitude to Glenn for his hard work and commitment to the Club since his permanent appointment in June 2001.
"This was demonstrated by his desire to return to active duty so quickly after his recent illness and I am sure all supporters recognise how dedicated he was to the club.
"The Board however feel that following relegation to the First Division the Club's best chance of returning to the Premiership at the first attempt would be enhanced by a change of manager."
Feel a bit sorry for the guy really, he should've gone before Christmas last season when it was obvious West Ham were gonna struggle. They've got a great team so surely with a better manager in charge they could've stayed up. After the brain thing I guess it became harder for them to sack him for compassionate reasons.
Brooking doesn't either but I expect his appointment albeit short term will prove popular with the fans. Can see him getting the job as long as it doesn't stand in the way of his television commitments
Not surprised by Roeder getting the sack and it looks like Brooking is this years Jimmy Case.
Wouldn't be surprised either if Houlier gets a move upstairs soon as Liverpool were bloody awful today.
Think you have hit the nail on the head Raphael, can't sack a man when he is on his death bed can you, at least wait until he is well enough to walk to the Dole Office.
West Ham have treated him terribly. They could have got rid of him after they went down, but deicded to keep him on, and get the abuse from the fans instead with all the sellings. He has got all the flack for things that has been the clubs decision.
Three games in to a season is a bloody stupid time to sack a manager. He should have gone while there was still time to avoid relegation or even once they were relegated. If he was to be given a chance in the first division surely he deserves a few more games to get it right?
I suppose this will start the managerial merry go round again, just hope Sir Steve isn't a target for them.