Carrying Cash more than SR 60,000 can lead to Jail
Like all countries in the world, Saudi Arabian rules require you to declare the amount of money you are carrying if it is more than allowed amount. Failure to make declaration will subject them to confiscation, and the bearer will be liable to legal penalties including jail.
The Saudi Customs department which comes under the Ministry of finance has set limit for the allowed amount at SR 60,000 or equivalent in foreign currency.
Travelers coming to or going outside Saudi Arabia are required to declare the money they are carrying if it exceeds more than SR 60,000 or equivalent in foreign currency. You can use this declaration form to declare the currency you are carrying.
This rules applies whether you are traveling through land, sea or airport.
There was a recent case where an expatriate who was arrested because he failed to declared the amount he was carrying. See Saudi Gazette