The temblor was centered about 16 miles northwest of the city of Talca. In the capital, about 136 miles to the north, people also felt the quake.
The shaking lasted for about a minute, sending panicked people running onto the streets. Chilean officials said there were some injuries, but none were major.
Some areas lost power and phone service was disrupted.
Residents along Chile's central coast were briefly warned to head for higher ground in case of a tsunami, but the warning was called off shortly after.
Residents were particularly alarmed in Constitucion, where much of the coastal downtown at the mouth of a river was obliterated by the tsunami caused by the 8.8-magnitude quake in 2010.
The Associated Press contributed to this story.