Users from the northern city of Milan to the Sicilian capital Palermo reported problems, with the issue mainly focused on fixed-line internet services.
Some soccer fans bemoaned interruptions to their streaming of the Serie A game between Spezia and league leaders Napoli.
“An international interconnection problem impacting the service at national level was detected. Analyses are underway to resolve the problem,” a TIM spokesperson said.
There was no indication that the problems were caused by hackers, Italy’s ANSA news agency reported.