The reigning champions were unable to break down a resolute Rangers defence in wet and windy conditions at Loftus Road as they looked to close to within two points of leaders Manchester United, who face Southampton at Old Trafford tonight.
Pablo Zabaleta hit the crossbar with a first-half header whilst QPR goalkeeper Julio Cesar produced a number of top quality saves to give the bottom club what could yet prove to be a valuable point as they strive to avoid relegation.
Mancini blamed his side's inability to provide the finishing touches to their play as the reason behind the dropped points.
"We lost two points, this is sure," he said. "But the season is long and I think I can say nothing because we played well, we had the chances but didn't score - that is all it is.
"We are disappointed with this result because we had a lot of chances to win, we dominated this game but when you play like this and don't score quickly it can be difficult.
"QPR defended very well and got players behind the ball and Julio Cesar was incredible."