You Do Need power plug adapter while traveling from Monaco to Italy.

Here is Why You Need An Adapter

The outlet and plug type used in Italy are C, F and L and in Monaco are C, E and F. This is how they look like.

Monaco

In Monaco, outlets of type C, E and F are in use.

Type C

Type E

Type F

Italy

In Italy, outlets of type C, F and L are in use.

Type C

Type F

Type L