Preston opened the scoring after 17 minutes when a long ball downfield from an Andy Lonergan free-kick was flicked on and assisted by Jon Parkin to Neil Mellor, who shot from in the six-yard box low and into the middle of the net with a deflection off Roger Johnson which wrong-footed the keeper.
Preston made it 2-0 after 40 minutes when Parkin was fouled by Roger Johnson.
Ross Wallace took a left foot, left-wing free-kick which was cleared by Roger Johnson but only to Preston captain Paul McKenna and from just outside the box he hit a rocket shot which went low and central and was deflected by Mellor into the back of the net.
Right on half-time, referee Mr Stroud awarded Cardiff a penalty when Billy Jones fouled Joe Ledley.
Ross McCormack hit the penalty into the bottom left but the Preston keeper Lonergan dived right to save brilliantly.
Preston made it 3-0 in the 51st minute when Mellor toe-poked the ball into the centre of the pitch and Parkin ran through before shooting under the keeper low into the middle of the net from the edge of the penalty area.
Chris Sedgwick found Mellor and he crossed the ball dangerously and Mark Kennedy headed into his own net after 54 minutes.
In the 75th minute on the left wing, Eddie Nolan found Sedgwick and he crossed the ball to Chris Brown who headed home to make it 5-0.
With four minutes to go, Wallace found Lee Williamson who beat the Cardiff defence before shooting inside the penalty area into the bottom left corner to complete the rout.