The town has a main population centre and five smaller villages within its administrative perimeter: Traditional local agriculture was based on the produce of the numerous olive, almond and carob trees of the area, as well as fruit and vegetable crops.

In recent years the quarrying of the stone of Ulldecona, a type of high quality marble, from the Serra de Godall hills has become a major income earner for the town.

Quarried since ancient times, the stone of Ulldecona has been used in the construction of important public works in Spain, such as the Pedrera in Barcelona, the Town Hall in Zaragoza and the airport of Madrid.

Presently it is also exported to different countries, such as the US (Hilton Hotel in Los Angeles), France, Switzerland (Town Hall of Geneva), South Korea, Saudi Arabia and China.

The most important customs of the people of Ulldecona are related to the staging of processions with gegants, musical bands and pubilles, as well as traditional dances and the releasing of bulls in the streets (bous).