A mouth-watering prospect of a tie sees United travel to Italy on Tuesday for the first leg of a last 16 UEFA Champions League tie that pits together again former sparring partners Mourinho and Sir Alex Ferguson.
The Inter man's record against his Scottish counterpart is enviable, with Mourinho's Chelsea having twice claimed the Premier League title during his three full seasons at Stamford Bridge.
"I have come up against United on several occasions and I know their style of play perfectly," said Mourinho.
"We will have time to prepare for our match against them. We do not fear Manchester United and we know we can beat them.
"That is despite recognising that they are a strong side with lots of qualities.
Primed"Come the day of the game we will be ready for United. I haven't decided whether we will play in the same manner as we did against Milan, as United have a style of play that is all their own."
Sunday's 2-1 win over neighbours AC Milan took Inter nine points clear at the Serie A summit and with United also flying, Mourinho anticipates an intriguing tie to ensue.
"The most beautiful matches to play are those against big sides, and in this moment United are at the top. They are a special team with special players.
"They have a lot of talent either on the field or on the bench, but my Inter have experience and quality.
"We know how to face big matches. And, especially, we know how to win them."