Uefa were looking into Mourinho's comments after he said that he was unhappy with Spanish referee Luis Medina Catalejo, particularly over his dismissal of a penalty claim by Inter striker Adriano in the first knockout round, first leg encounter.
A Uefa spokesman said: "There will be no action taken."
This decision means the Portuguese tactician will not face a touchline ban for the second leg at Old Trafford on 11th March.
The possibility of sanctions arose after Mourinho vented his frustration about Cantalejo's performance, saying: "When we go there [to Old Trafford] we will not have the same referee.
Protection"If we have another referee that gives so much protection to the away team, then it will be us who go to the quarter-finals.
"Everything was against us, every little detail. You watch how many free-kicks they had and we had. The way we got yellow cards and they did not. I think the tendency was clear.
"Hopefully in the next game the referee will be on our side."