It upheld a ruling that a man had developed acoustic neuroma, a benign tumour of the head, as a direct consequence of using a mobile phone for long periods.
Judges at the Court of Appeal in Turin said they reviewed all the scientific studies and concluded that there was "strong evidence" that EMF (electro-magnetic field) frequencies from a mobile phone could cause the cancer.
It's the second time an Italian court has ruled that mobile phones can cause cancer. A 2010 ruling in favour of an Italian worker was upheld two years later by the country's supreme court.
In the latest ruling, the appeal court judges noted it was difficult to find good independent research that hadn't been funded by the mobile phone industry. These clear conflicts of interest should be highlighted from the offset, the judges said, and that less weight should be given to them.