Kevin Doyle broke the deadlock on the hour, running clear following a Dave Kitson flick and beating Leicester keeper Rab Douglas with a neat finish.
And substitute Brynjar Gunnarsson made certain of yet another win for the Royals when he headed home Nicky Shorey's free-kick three minutes from time.
Steve Coppell's side are now unbeaten in 25 games and show no signs of relinquishing their stranglehold on a promotion place this season.
Reading have not been beaten since the opening day of the season and look hell bent on avoiding a repeat of last season when they led the Championship on Boxing Day before falling away with an 11-match winless streak.
Leicester came to the Madejski Stadium having failed to win in December, though their last victory was over Reading's title rivals Sheffield United.
But Craig Levein's side showed few signs of repeating that upset as they attempted to frustrate a Reading side in menacing form.
In truth, Reading frustrated themselves too, Bobby Convey and Steve Sidwell wasting good early chances to put them ahead.
The home side were denied what appeared to be a clear penalty when Douglas clattered into Kitson after the striker had nipped between the keeper and defender Patrick McCarthy.
At the other end, Mark De Vries was twice denied by American keeper Marcus Hahnemann with efforts either side of half-time but Leicester rarely threatened.
Doyle finally made a deserved breakthrough for Reading on the hour when he took advantage of Patrik Gerrbrand's slip to run clear and shoot beyond Douglas.
Convey went close to a second with a cheeky flick that bobbled narrowly wide, but it wasn't until three minutes from time that Reading made certain of victory.
Doyle was fouled wide on the left by McCarthy and Shorey's inviting centre was headed home by Gunnarsson when only just on as a substitute.