Georgian President Mikhail Saakashvili has dismissed his army chief, Zaza Gogava, following a review of the conflict with Russia in August.
Mr Saakashvili said "the enemy" was still at Georgia's door and he had to address "shortcomings" in the military.
Last week, Mr Saakashvili dismissed the country's prime minister, Lado Gurgenidze, in a cabinet shake-up.
The president has been facing growing criticism in Georgia over the handling of the South Ossetia conflict.
Mr Saakashvili said he wanted to thank Mr Gogava but that following a review of August's events he had decided that "the shortcomings we uncovered must be eliminated".
"We must not forget that the enemy still stands at our door," he said, in what was taken to be a reference to Russia.
Vladimir Chachibaya has been appointed chief of staff in Mr Gogava's place, he said.
The conflict in the region began on 7 August when Georgia tried to retake its breakaway region of South Ossetia by force after a series of lower-level clashes with Russian-backed rebels.
Russia launched a counter-attack and the Georgian troops were ejected from both South Ossetia and Abkhazia, a second breakaway region, days later.
Russian forces remain in the two regions, and Moscow has backed their declarations of independence.
7 months ago