The industrial cities at Jubail and Yanbu have played a key part in the Kingdom's determination to develop hydrocarbon-based and energy-intensive industries. The Royal Commission for Jubail and Yanbu, established by a Royal Decree, dated 21st September 1975 (16 Ramadan 1395 AH), has created the basic infrastructure for these two cities, often described as the jewels in the Kingdom's industrial crown.
Jubail is the largest industrial city. By 1999, it had more than 70,000 full-time residents, 17 basic industrial plants, 16 secondary industrial plants and 100 supporting and light industries plants, as well as a dedicated desalination plant, a vocational training institute and a college. By 2006, the number of full-time residents had increased to 94,100.
Yanbu is a major industrial site with a modern port from which products manufactured locally and in other areas of the Kingdom are exported. By end of 1999, Yanbu had 72,740 full-time residents, eight basic industrial plants, eleven secondary industrial plants and 33 supporting and light industrial plants.