Officials said the dead included people who were crushed by collapsing walls or died from heart attacks.
The government evacuated Chile's northern coast and President Michelle Bachelet declared the area a disaster zone, promising troops and police reinforcements to maintain public order while damage was repaired after landslides blocked roads.
About 300 prisoners took advantage of the emergency and escaped from a female jail in Iquique.
About 26 of the women were soon recaptured, authorities said, while security forces fanned out through the area amid reports of power outages and isolated looting.
The Pacific Tsunami Warning Center said the quake generated a large tsunami, with the biggest wave reported at about 6ft high.
The Chilean navy said the first big wave hit the coast within 45 minutes of the quake.
Ms Bachelet, who just returned to the presidency three weeks ago, tweeted: "The country has done a good job of confronting the emergency.
"I call on everyone to stay calm and follow the authorities' instructions."
A tsunami warning was issued for the Pacific coast of Mexico through Central and South America. A tsunami advisory was issued for Hawaii, although no disaster was expected to hit the island state.
The quake caused power cuts in Peru and was felt as far away as Bolivia.