The Russian-made S-300 air defense system is now completely deployed in Syria's northwestern Masyaf.
Masyaf is near Homs and Hama, both of which have suffered recent airstrikes.
An image published Sunday by ImageSat International shows four S-300 batteries and two advanced radar systems, and the IDF announced that the system seems fully operational.
An Israeli satellite imagery analysis company noted that until now, only three of the four surface-to-air launchers had been fully erected.
Maariv noted that the images also show a road leading from the S-300 to a nearby base.
Russia gave Syria at least some of the the S-300 systems free of charge, in a move criticized by US Secretary of State Mike Pompeo, as well as by Israel, which fears the technology might fall into the hands of the Hezbollah terror group.