The crash took place Avellino, outside Naples, after the tour coach collided with cars that had been slowed by heavy traffic, police and rescuers said.
Rescuers worked throughout the night at the A116 autostrada, a major motorway crossing southern Italy, searching the wreckage for survivors (see video, above).
Hours after the crash, rescuers reported that 37 bodies had been found. Most of the dead were pulled from the coach though others had been found under the wreckage. 10 people have been taken to hospital.
Reports suggest as many as 49 Italian tourists were travelling on the coach when it crashed through the highway barrier.
The driver is said to be among the dead.
‘Normal’ speed
It is understood the coach was returning to Naples after an excursion in the south. The tourists were all from small towns near Naples.
A reporter for Naples daily newspaper Il Mattino told Sky TV, reporting from the scene, that some witnesses had said the coach had been going at a “normal” speed on the downhill stretch of the road when it suddenly veered and started hitting cars. He said some witnesses thought they heard a noise as if the coach had blown a tyre.
A local prosecutor has arrived at the scene to begin an investigation into the cause of the crash.