The Men in Green did concede three tries in the second half after keeping Italy out in the first period, but Joe Schmidt's side were rarely tested in earning their second victory of the tournament.
It was a better performance from Schmidt's men following last weekend's 15-13 win over France, as centre Robbie Henshaw and left wing Jacob Stockdale both crossed for braces.
Ireland took advantage of a frantic first five minutes - both sides spread the ball wide, but the Men in Green won the first lineout after Italy failed to keep the ball alive.
The hosts suffered an early setback as prop Tadgh Furlong suffered a hamstring injury, but Ireland pressed on regardless - they were in front after 11 minutes when Henshaw ran a strong line between two Italian defenders and burst over from close in.
Italy had failed to muster any meaningful possession in their opponents' half, and were pushed back into their own 22 once more when Bundee Aki bundled over after a strong scrum drive.
Schmidt's side earned their bonus point after 35 minutes as Aki, who sold a dummy to the Italian defence, accelerated through the gap before switching the ball outside to a supporting Keith Earls. The winger made no mistake with the finish.
It took 39 minutes for Italy to register any potential threat, but Braam Steyn failed to keep the ball in his grasp from a lineout.
Ireland wasted no time in extending their 28-0 advantage, as Henshaw crossed for his second try four minutes after the restart. The centre intercepted a loose Sergio Parisse pass to run clear, but a late challenge from Tommaso Benvenuti saw the Irishman injure his arm going over the whitewash.
Stockdale outpaced an Italy defender to cross for his second, before Italy earned their third try as full-back Matteo Minozzi beat Jordan Larmour to the corner to squeeze over.
The visitors could have left Rome with a bonus point of their own late on, but Earls raced back towards his own line to pull down Mattia Bellini.
Ireland play Wales in round three next weekend, while Italy face France.