The move is aimed at "standing by and supporting the brotherly Egyptian people, and to reduce the pressure on hospitals there," said a Saudi official cited by SPA state news agency.
The hospitals will come with a full staff of doctors and technicians, the unnamed official said.
King Abdullah yesterday pledged the kingdom's support to Egypt's fight on "terrorism", as the army and security forces continued a bloody crackdown on supporters of deposed Islamist president Mohamed Morsi.
The government today said that 173 people had died in the past 24 hours alone.
Following Morsi's ouster by the army last month, Saudi Arabia, the United Arab Emirates and Kuwait pledged a combined total of USD 12 million in aid to support Egypt's faltering economy.