The websites of the Tel Hashomer and Assuta medical centers came under cyber-attack on Wednesday.
Both websites, which represent two of the largest medical centers in central Israel, were down for maintenance throughout the morning.
A spokesman for Tel Hashomer confirmed the site came under cyber attack saying no harm came the site or its content.
Around noon Wednesday, the Assuta Medical Center reported a similar cyber attack. The hospital's website's firewall successfully overcame the onslaught.
Wednesday's cyber-attack is only the latest in a strike-counterstrike series of online skirmishes between Israeli and Arab hackers that began when a Saudi hacker published Israeli credit card data online.
The attacks have included social networking credentials, corporate and stock exchange websites, consumer and credit card data in both Israel and Arab countries.
On Wednesday, Israel's National Cyber Command (NCC) and the Counter Terror Bureau (CTB) launched Israel's first official cyber emergency drill dubbed "Lights Out."