The matches were due to take place on Wednesday and yesterday night at Juve's Allianz Stadium and Napoli but the government's restrictions on who could attend sporting events weren't enough to guarantee safety.
The decision as for Juve was made on the basis of "assessments made by the Piedmont region's crisis unit" and regional health councillor Luigi Icardi, who insisted on "avoiding large public gatherings".
No new date has yet been fixed for the second leg of the last four tie, which is level at 1-1 following the first match at the San Siro last month.
As for Napoli-Inter, whose 1st leg score was an away 0-1 win for the Partenopei, postponement was due to security reasons and at present no date is yet to be fixed.