It is also the county seat of delegation of the same name which had 18,335 inhabitants at the 2004 Census and 15,957 at the 2014 Census (National Institute of Statistics) and brings together, in addition to the city of Ghomrassen, the villages of Ksar Hadada, Oued El Khil, Elferch, Elhorria, and Ksar Elmorabitin Guermassa.

The city, located about 480 km (300 mi) south of the capital Tunis and surrounded by mountains, is built on the site of an ancient oasis.

Administratively, the city is divided into several sectors or Imad, whose authority is embodied by the omda, which can cover both urban and rural areas.

[citation needed] A myth told by the inhabitants of Ghomrassen indicates that the city name comes from two words, Ghom Rassi نغم راسي, given by one seven brothers from the region of el-Hamra Seguia (northern Western Sahara) to 15th century to populate the south-east of Tunisia and from the confederation of Werguemma كنفدرالية ورغمة.

This brother had settled in the location of the future Ghomrassen he later founded, while his brothers were scattered in the southeast of the country to achieve the key groups of people in the region: Wederni الودرني and Jlidi الجليدي founded Tataouine, Touzni التوزني Medenine and Ben Gardane, Houioui الحويوي Beni Khedach and Khzouli الخزولي Umm Ettemr.