The Stamford Bridge boss has indicated the club is looking for a striker, but ruled out the possibility of swapping Belgian sensation Eden Hazard for Edinson Cavani
Ibrahimovic has been in sensational form for PSG, most recently scoring a hat-trick in a 4-2 win over Toulouse.
Mourinho remains in contact with the Swede after their time together at Inter, but says the striker is happy in Paris.
"Zlatan to Chelsea? It’s impossible," Mourinho told Canal Football Club. "He’s happy at Paris. I know because he is my friend and we are in touch. PSG, with all its wealth, would never open the door. That’s mission impossible."
However, Mourinho did suggest a move for Monaco striker Falcao could be a possibility in the future.
He said: "I have a team, but no striker. Falcao does not have a team. A player like him can't play in front of 3,000 people. Monaco is a club to end [your career with]."
The Stamford Bridge boss also ruled out the possibility of a swap deal involving Edinson Cavani and Eden Hazard.
"Eden is our boy," he added. "We want him to stay for ten years. We want to build the team around him. He’s a player with the style of football that we want to have in our team."