Mourinho has never been far from controversy in his career to date and Koeman, who is in charge of Dutch side Feyenoord, admits that his behaviour may upset opponents.
However, the former Barcelona midfielder confesses to be a fan of the Portuguese manager, describing him as someone who creates a winning mentality among his players.
He told The Mirror: "Many people in the game can't stand Mourinho - I am the opposite.
"Mourinho may not create the most beautiful style of football. But he does create winners. Nobody turns his players into winners more than he does.
"He comes out with strong stuff. He did it before the PSG match in London. But he achieves what he promises. My God, I can only show huge respect then."
Mourinho's Chelsea take on Swansea City in the Premier League on Sunday.