Sources from the state-controlled Saudi Telecom, which is the kingdom's biggest telecom operator by market share, said the ban on Blackberry Messenger was due mainly to security concerns.
Saudi Arabia has about 700,000 BlackBerry users of which some 80 per cent are individual users.
The device is a big success, especially among youths who use its Messenger function to interact with members of the opposite sex and exchange jokes and pictures in a deeply conservative society.
The United Arab Emirates also threatened on Sunday to ban some BlackBerry services unless its maker, Research in Motion (RIM), gives it access to encrypted messages.
India is also in talks with RIM over how information is managed on the devices. Like the UAE, it has cited security concerns in pushing for greater access to encrypted information sent by the phones that gets routed through the Canadian company's computers overseas.