The magnitude-4.8 quake struck at a depth of 15.5km (9.6 miles) 35km north of the city of Lucca, officials said.
The tremor was felt as far away as Milan and Florence, Italian media say. There were no immediate reports of injuries or damage.
Italy is prone to earthquakes. In 2009 almost 300 people died in a quake in L'Aquila in the central Abruzzo region.
Italy's National Institute of Geophysics and Volcanology (INGV) said the quake struck at 15:48 (14:48 GMT), with its epicentre in Garfagnana.
Several aftershocks of lower magnitude were felt across a large area.
Phone lines were down and power supplies were cut in the Garfagnana area, Italian news agency Ansa reports. As a precaution, schools were said to have been evacuated in the immediate vicinity and were to be checked for any damage.
In Milan, top floors of tall office blocks shook and the quake was also felt in the cities of Bologna and Modena.
In Lucca, people poured out into the streets, Ansa said.
Last May, two earthquakes in the same area left more than 20 people dead. The strongest tremor was magnitude-6 and caused significant damage.
Alessandro Amato of the INGV said the latest tremor "came out of nowhere", and described it as a classic earthquake for the area - "medium-strong" and "fairly shallow".
Italy is still trying to recover from the aftermath of the deadly earthquake in L'Aquila.
Six scientists and an ex-official were convicted of multiple manslaughter in October 2012 for giving a falsely reassuring statement.
The group, all members of the National Commission for the Forecast and Prevention of Serious Risks, were accused of having provided "inaccurate, incomplete and contradictory" information about the danger of the tremors felt ahead of the 6 April 2009 quake.
At a meeting a few days before the deadly quake, they had told officials in L'Aquila that, while a major earthquake was not impossible, it was not likely.
On the night of the quake, many people are said to have remained in their homes and died because of the advice, while others who had decided to remain outside in the street survived.
An earthquake has shaken parts of northern Italy, forcing some residents onto the streets.