Ciro Immobile Nicolo Barella Lorenzo Insigne and Domenico Berardi all scored for the hosts who will open the Euro against Turkey next Friday.
In the absence of Paris Saint-Germain midfielder Marco Verratti, who is nursing an injured knee, Jorginho, a Champions League winner with Chelsea, and Barella quickly set the tempo for Italy.
Italy's strikers Lorenzo Insigne and Ciro Immobile wasted early chances, before Immobile of Lazio broke the deadlock in the 3rd minute.
Barella, who injected energy from midfield, added a second before half time.
Immobile set up Insigne to score the third with a deflected shot.
Berardi rounded off the party in style, much to the delight of the few thousand spectators in the venerable Dall'Ara Stadium.
They also warmly welcomed the debut of Sassuolo striker Giacomo Raspadori, the surprise pick on the 26-man squad, with 12 minutes left.
While Italy's attack enjoyed itself, the defence maintained their defensive solidity with an eighth consecutive clean sheet.
The Czechs, who open their Euro campaign against Scotland in Glasgow on June 14, started brightly before the home team took full control.
The only real scare for Italy manager Roberto Mancini came when Leonardo Bonucci limped off in the first half after twisting his right knee, but the Juventus defender returned and finished the game.
Italy are undefeated in 27 matches, since September 2018.