The 30-year-old striker will be available to feature for QPR against Burnley at Loftus Road in the Championship on Saturday.
"It was all agreed pretty quickly," he told the London club's official website. "I jumped at the chance to come here to be honest. The club's in a great position for a tilt at promotion and I can't wait to be part of it.
"It was a massive draw to know I'll be part of a promotion push and obviously the manager played a huge role in my decision to come here as well.
"The squad here have enjoyed a really positive first half of the season and everyone is looking forward to tomorrow. It's a big game and I'm just looking forward to hopefully being involved in some capacity."
QPR are currently second in the league table with 55 points from 27 matches.