But the Llaima volcano's eruptions were slowing by Wednesday afternoon, so a larger evacuation did not appear necessary.
The evacuees included about 200 tourists, National Forest Service employees and others in the surrounding Conguillio National Park, about 400 miles south of Santiago.
Hundreds spent the night outside or in shelters in Melipeuco, a town of 5,000 near the Llaima volcano. Others fled to communities farther away, but most were returning Wednesday.
Chile's Emergency Bureau director, Carmen Fernandez, said a larger evacuation wasn't necessary despite television images showing thick smoke and lava flowing from the crater.
"There are no signs yet of an increased risk," Fernandez said. "There is some flow of lava, but not in a continued manner yet."
The bureau said the eruption was decreasing Wednesday and explosions were less frequent and milder, even as Argentina reported a heavy presence of gas and ash across the border.
The 9,400-foot high Llaima, one of the most active among some 60 active volcanoes in Chile, has not had a major blast since 1994.