Pavarotti, who underwent surgery for pancreatic cancer last year, was brought to Modena's Polyclinic two days ago, said manager Terri Robson. Earlier a hospital spokesman had said Pavarotti was admitted Wednesday.
Robson and officials at the hospital declined to give the reason the 71-year-old tenor was hospitalized, but local daily Il Resto del Carlino reported that it was pneumonia.
Robson said she would issue a statement later.
The paper said Pavarotti was diagnosed with pneumonia as he was vacationing with his family at his villa in Pesaro, a seaside resort on the Adriatic some 124 miles southeast of Modena.
Pavarotti had been preparing to leave New York in July 2006 to resume a farewell tour when doctors discovered a malignant pancreatic mass, Robson said at the time. He underwent surgery in a New York hospital, and all his remaining 2006 concerts were canceled.
Pancreatic cancer is one of the most dangerous forms of the disease, though doctors said the surgery offered improved hopes for survival.