Berlin: Hamburg SV sacked coach Bruno Labbadia on Sunday after they suffered a fourth straight Bundesliga defeat when they were beaten 1-0 by Bayern Munich on Saturday.
"This step, given the current trend, is necessary," said Hamburg sports director Dietmar Beiersdorfer. "I am convinced that we have to make a change in the coaching position in order to turn our disappointing season start around."
"After the long pre-season preparation and the games so far we have to admit that our development does not match our expectations," Beiersdorfer said in a statement.
Hamburg have one point from five matches, having lost their last four, and are just one place off the bottom of the table.
Labbadia, who was in his second spell at Hamburg, leaves after 18 months in charge, having helped them stay up at the end of the 2014-15 season following a dramatic relegation playoff against Karlsruhe.
Hamburg said they will announce his successor early next week.