United have confirmed that Nani passed his medical in Manchester on Wednesday.
The Portuguese international is set to join the Reds after United agreed a deal with his current club Sporting Lisbon late last month.
Following the completion of his medical at Carrington, the 20-year-old winger was given a tour of Old Trafford.
Nani recently expressed his delight at the prospect of joining United, saying that he is prepared to work hard to earn a place in Sir Alex Ferguson's team.
"This is a dream move," he told reporters recently. "It won't be easy to get a place in the first team, but I am ready for the challenge."