Both clubs had bids accepted by Marseille for the France international before Remy snubbed the Magpies in favour of a switch to the Hoops, despite their position at the bottom of the Premier League table.
He said: "It is true that I hesitated between Newcastle and QPR. I went to meet the staff at Newcastle but there came a time that I had to make a decision.
"I made my decision based on two factors. Firstly, I already knew Harry Redknapp and secondly, I am really excited by the project QPR have here for the future.
"It is true that it is a big challenge and that the team are currently in a tough situation, but since Harry has been here, things have changed a great deal. It is up to us in the second half of the season to work hard and stay up."
Remy scored on his debut last weekend as Rangers drew 1-1 with London rivals West Ham United.