Israel has deployed all of its missile defences, while citizens have scrambled for gas masks in preparation for a potential Syrian retaliatory attack.
On Wednesday Israeli Army Radio revealed the mobilisation is a precautionary measure should Western powers carry out threatened strikes on Syria.
Army Radio did not say how many of its air defence batteries meant to knock out incoming missiles were mobilised, according to the Jerusalem Post.
The news comes after the country ordered a special call-up of reserve troops today as citizens lined up at gas-mask distribution centres.
Facing a potential imminent attack by America and other Western powers over its alleged use of chemical weapons, Syria has hinted it could shoot back at its old foe, Reuters reported.
Damascus and Tehran have said Israel would be targeted if the West attacks Syria, even though Israel has not taken an active role in the civil war there.
Israel's security Cabinet approved the call-up of "hundreds" of reservists after Prime Minister Benjamin Netanyahu discussed the dramatic measures with his top security advisers today.
Afterwards, he urged people to remain calm while also approving special precautionary measures.
"There is no reason to change daily routines," he said.
"At the same time we are prepared for any scenario."
He said the Israeli military "is ready to defend against any threat and to respond strongly against any attempt to harm Israeli citizens."
An anonymous military official said several hundred troops were being mobilised, though there was authorisation to call up thousands more if needed, AP reported.
Meanwhile, Israeli demand for gas masks has quadrupled in recent days, said Maya Avishai of the Israeli postal service, which oversees gas mask distribution.