Strikes on Italian trains are infrequent enough that you might travel through the country many times and never have to deal with one. It only takes one instance of having travel plans thwarted by an unexpected strike, however, to ruin a trip.
Note that the word in Italian for strike is "sciopero" - be on the lookout for it in newspapers and at train stations!
The good news is that Italy schedules their strikes in advance, meaning there are some ways you can avoid dealing with them entirely even if you're there during a strike. The bad news is that the best resources for tracking strikes are in Italian.
The very best resource to consult is the Commisione di Garanzia Sciopero's site, which is regularly updated with information on strikes around the country, both having to do with trains and other sectors. If you have a little understanding of Italian, or know someone who does, this can be an invaluable resource. An English site that's good, if not as detailed as the Italian site, is Easy Travel Report. Click on the link for "Italian Strikes" to see Italy information.
By checking the strike schedule ahead of time, you may be able to adjust travel plans and avoid a travel day when a strike is going to take place.
Even on days when there are strikes scheduled, Trenitalia has what it calls "guaranteed minimum transport services." In other words, there are some trains that will run every day despite a strike so that an entire country doesn't shut down. It's relatively minimal service, compared to normal schedules, and it focuses on commuter hours - 6-9am and 6-9pm from Monday through Saturday.
Tickets for these trains can be reserved in advance just like they can be at any time, but of course with such limited service the seats will get reserved quickly. Planning ahead means you might get one of them.
If you don't find out about a strike until you arrive at the train station, be prepared with lots of patience. Trenitalia staff should do their best to get you booked on the next available train. If there are no other trains available, you can request a cancellation and strike refund directly at the train station.*
You can, instead, wait until you return from your trip to claim your refund. The ItaliaRail Customer Service department can assist you in filling out a refund request, or send one to you to fill out yourself.**
Sometimes a strike officially begins when you are already in transit. Trains that are traveling when a strike begins and are not canceled in advance at their departure station will normally reach their final destination, provided those stations can be reached within one hour from the strike's start. If trains are not able to make the one hour time limit then they may terminate at the next station and before your stop is reached. In the event that this happens, Trenitalia will assist you with an alternative connection provided there are still trains available on that day to reach your final destination.
Please feel free to contact us directly by email (firstname.lastname@example.org) or phone (1-877-375-7245) if you have any questions.
* Information on whether or not your fare is eligible for cancellation and strike refund prior to the strike date can be found under the fare rules stated for your ticket.
** If you wait to process the refund when you return home, it could take upwards of six months to receive your refund. Trenitalia will contact you directly. ItaliaRail has no say, and plays no part, in the decision Trenitalia makes about your refund.