The Qadiriya is the largest and most highly organized brotherhood in Mauritania. Founded in Mesopotamia in the twelfth century by Abd al Kader al Jilani, it spread to Africa in the fifteenth century. Like all brotherhoods, the Qadiriya includes some emotional mystical elements, but it also stresses learning and Islamic education as the way to find God. All members of the Qadiriya are directed to follow the precepts of humility, generosity, and respect for their neighbors regardless of religious beliefs or social standing.

The Qadiriya brotherhood has had two main branches in Mauritania, the Sidiya and the Fadeliya. Although the Sidiya has been most influential in the vicinity of Trarza--where the family and followers of the brotherhood's founder, Shaykh Sidiya Baba, were centered--it has also been important in Brakna, Tagant, and Adrar. The Fadeliya, founded in the early nineteenth century by Mohammad Fadel, has been centered in Oualāta and Atar.

Data as of June 1988