Their excellent home form continued as they registered their ninth win at Deepdale this season and it was new boy Patrick Agyemang, a recent signing from Gillingham, who opened the scoring.
Agyemang had the ball in the back of the net after just 14 minutes but the referee disallowed the goal for a foul after the striker had turned Paul McKenna's corner home from close range.
Two minutes later Eddie Lewis' free-kick was met by both Brian O'Neil and Agyemang but it was the latter who got the final touch as he powered a seven-yard header into the net.
Preston made it 2-0 after just 25 minutes when Graham Alexander took a quick free-kick that caused panic in the Reading defence.
Andrew Hughes managed to head the ball past his own keeper Marcus Hahnemann as the Royals' poor away form continued.
Reading's Paul Brooker had two off-target shots before the break while at the other end Richard Cresswell's close-range effort was saved by Hahnemann.
Preston made it 3-0 in the 67th minute when Agyemang ran clear down the left-hand side and squared the ball to Eddie Lewis who fired a shot into the top left-hand corner of the net.