The quake struck at 6:32 pm (2232 GMT) about 108 kilometers (67 miles) northwest of the capital Santiago, at a depth of 35 kilometers, the US Geological Survey said.
The national emergency office ONEMI said the temblor shook Santiago and five other regions in the South American nation.
More than five million people live in the capital, and the quake shook buildings for 30-40 seconds, causing panic even in a country used to temblors.
"There have been some power outages but no reports of damage to buildings or infrastructure... though this is still preliminary information," ONEMI chief Miguel Ortiz said.
The earthquake did not create a tsunami risk, according to the water and oceans service.
Chile is one of the most seismically active countries in the world, and is located in the so-called Ring of Fire area of the Pacific Ocean basin.