Travelling to USA with italian passport

 It is difficult to ascertain the validity of your passport without looking at it, but that statement is a bit strange. Normally, passports are valid to travel worldwide. Anyway, have a look at these instructions from the US Embassy in Italy:www.usembassy.it/visa/

 Doesn't "This passport is valid for member countries of the european union and for transit through non eu countries" effectively mean valid to travel worldwide? My wife's Italian passport instead says "This passport is valid for all Countries whose Governments are recognized by the Italian Government"  That's actually a bit more restrictive than "This passport is valid for member countries of the european union and for transit through non eu countries". BTW, if you're a US citizen you must enter/exit US on your US passport. As for the marca da bollo, it's a tax, legally you should do it.  No one will check in the US or on return to UK though, only if you enter Italy.  But do the right thing- Italy's running a budget deficit of 9.3% of GDP- she needs your money!  

I am not so sure about that mention. To me, it sounds as if that particular passport is only valid within the EU and to transit through non EU countries (i.e. Switzerland). Just check its validity as the US Immigration is not easy to deal with if something is wrong. I have checked my EU passport (Spanish) and there is no restriction or mention regarding the countries it is valid for. 

 No, I'm afraid it's a poor translation of a false friend. Rather than "transit through",  transitare means "to pass", as in "pass into the country" (think passport).  There is no variant of Italian passport that only allows one to travel within EU and only "transit through' non-EU countries to reach other EU countries.  BTW for EU countries, you can visit with only your  carta d'identità.  Furthermore, you can go to some non-EU countries (e.g. Switzerland, Norway and Croatia-  for more download Documenti validi per l'espatrio ) with only your carta d'identità, no passport needed.    A passport permitting only the same would be rather useless.My wife's passport was issued at Los Angeles consulate.  It's 2005 pre-lettura ottica, so I suspect you're right- they've "improved" the wording, further confusing us poor Inglesi.