Syrian state television quoted a military source as saying the army and allied militias had taken "complete control over the city of Palmyra," according to a report.
The Britain-based Syrian Observatory for Human Rights said gunfire could still be heard in the eastern part of the city on Sunday morning, but that the bulk of ISIL's forces had retreated.
Palmyra, known as the "bride of the desert", used to attract tens of thousands of tourists a year before the conflict started in 2011.
The army was now trying to dismantle booby trap bombs in some of the city's neighborhoods, sources told Al Jazeera.
In May, ISIL took Palmyra in a matter of days and later demolished some of its best-known monuments. The fate of the remaining artifacts is unknown.
Capturing the city will be seen as a major strategic victory for President Bashar al-Assad's government. It opens up for a possible advance much of the eastern desert, stretching to the Iraqi border to the south and ISIL's heartlands of Deir al-Zor and Raqqa to the east, as noted in the report.
