The transportation ministry said late Thursday that Italian ships already at sea will have to return to port and undergo tests on all crew and passengers.
Those not positive for COVID-19 will be asked to self-isolate and to monitor their health.
The notice runs until April 3.
Prime Minister Giuseppe Conte said Thursday that all Italian restrictions — including the shutdown of most businesses and a ban on public gatherings — will have to be extended well into next month.
Italy has a thriving cruise industry that employed 120,000 people and was Europe's largest in 2017.
Several cruise ships have experienced coronavirus outbreaks that saw them blocked from various ports during the virus crisis.
The Diamond Princess cruise ship that was quarantined at a port in Japan was under the command of Italian captain Gennaro Arma.