I just received an email from the manager of the Rome apt where we will be staying in a few weeks. Among other things, he is requesting the numbers of all of our US passports. Is this an unusual request?

Not at all. Italian law requires that the manager register you with the local police. You won't be able to stay there unless you comply.

Many European hotels will make a copy of the info page of your passport, some will even hold your passport for the first 24 hours of your stay. I don't find it unusual that an apartment manager would ask for the same info.

In my 4 trips to Italy, I have showed my passport upon arrival but have never told anyone my number before hand.

The hotel will take your passport on arrival to register with the police - since they do this every day. I can understand someone renting an apartment wanting info in advance so they can do this when they get the chance - not wait until the renter arrives to pick up the keys.

You're going to have to provide the info at some point - and if you trust the people enough to rent an apartment don;t know why you would be concerned abut the passport # (they can;t make fakes without your photo and other info).

Thanks for the info, everyone. You've put my mind at ease!