Youl Mawene scored an injury-time equaliser for Preston, who have still to win at home this season.
Mawene headed home from 12 yards to cancel out the opener from Danny Shittu, who had pounced to head home a Kevin Gallen corner.
Carlo Nash saved from QPR trio Lee Cook, Paul Furlong and George Santos.
Danny Dichio and Chris Lucketti headed wide for Preston, while Patrick Agyemang missed a promising opening and Simon Royce saved from David Jones.
Preston manager Billy Davies:
"We lost a very sloppy goal. We never played that well in the first half - in the second half, we created more chances.
"That was a strong physical side we played. I think we handled them well, but then lost that goal.
"We showed determination and character to come back and get a point."
QPR boss Ian Holloway on Youl Mawene not getting sent off for his challenge on Paul Furlong at the start of the second half:
"It was a questionable decision which wasn't made. In my 20-odd years I have never seen anything like it.
"The bloke brought him down. We were not even given a free-kick.
"We knew it was going to be a difficult place to come to but I felt we deserved all three points."
Preston: Nash, Mears, Mawene, Lucketti, Davidson, Sedgwick (Nowland 70), Jones, McKenna, Lewis Neal, Agyemang, Dichio (Hibbert 71).
Subs Not Used: Alexander, Hill, Parillon.
Goals: Mawene 90.
QPR: Royce, Bignot, Shittu, Evatt, Dyer, Lomas (Doherty 56), Gallen, Santos, Cook (Ainsworth 76), Nygaard, Furlong.
Subs Not Used: Sturridge, Cole, Moore.
Goals: Shittu 62.
Ref: M Pike (Cumbria).
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