Recent reports have claimed United are tracking the highly-rated attacking pair as they look to bolster their squad.
Hamsik has been linked with loads of clubs in Europe, all coming after the player has been putting in some brilliant performances for Napoli for the last year or so.
Cavani is attracting just as much attention, again because of his performances since his arrival.
But De Laurentiis says the duo are going nowhere.
"When I read of the €40 million offer from Alex Ferguson for two of our players I started to laugh," De Laurentiis told Radio Marte.
"We have to stand up a compact team which above all has heart. There is no point talking about exciting names."