The 20-year-old becomes Neil Warnock's first signing of the January transfer window and will wear the number 33 shirt at Loftus Road. Macheda spent a similar stint with Sampdoria in Serie A last season and hopes to gain valuable first-team experience during his time in west London.
"There is a lot of competition at Manchester United, there are some very good strikers there," Macheda told www.qpr.co.uk. "But I am still young and I need to get more experience in the Premier League. I am here to train hard firstly and then I hope to play a big part in the games."
Macheda is eligible for today's vital Barclays Premier League encounter with Norwich and is looking forward to playing with his new team-mates.
"I was attracted by the challenge and by the players that QPR brought in during the summer," he said. "There are some very big players at the club now and I am really looking forward to training and playing with them.
"I also know the fans are very, very passionate, and this interested me also."
Macheda revealed Rio Ferdinand - brother of Rs defender Anton - advised him to link up with Neil Warnock's side.
"I spoke with Rio and he told me that QPR is a very good club and that if I did come here it would be good for me and would help me to develop as a player," he said. "I am looking forward to this challenge. Now I want to work hard for the team and for the fans."
The former Lazio striker came to the public's attention when he scored an injury-time winner on his Manchester United debut against Aston Villa in April 2009.
Macheda scored a further four goals for United but his first-team chances have been limited, which QPR manager Warnock believes makes the loan deal a "great opportunity for both parties".
Source: PA
Source: PA