Race as such plays little part in defining regional or group identity in Pakistan, and no ideal racial type is accepted by all Pakistanis. The population is a complex mixture of indigenous peoples, many racial types having been introduced by successive waves of migrations from the northwest, as well as by internal migrations across the subcontinent of India. Aryans, Persians, Greeks, Pathans (Pashtuns), and Mughals came from the northwest and spread across the Indo-Gangetic Plain, while the Arabs conquered Sindh. All left their mark on the population and culture of the land. During the long period of Muslim rule, immigrants from the Middle East were brought in and installed as members of the ruling oligarchy. It became prestigious to claim descent from them, and many members of the landed gentry and of upper-class families are either actually or putatively descended from such immigrants. In 1947, when Pakistan and India became independent, there was another massive migration, of a different character, when millions of Muslim refugees were uprooted from different parts of India and settled in Pakistan; an equal number of Hindus were uprooted from Pakistan and driven across to India. This development further complicated the racial mixture of the population of the various regions of Pakistan.

By the early 1990s Pakistan's population was divided into five ethnic groups, defined broadly. The Punjabis constitute the majority, with more than 55 percent of the population; the Sindhis account for another 20 percent, the Pathans and the mujahirs for about 10 percent each, and the Balochs for about 5 percent. There are subgroups within each of these five categories. The Arains, Rajputs, and Jats—all Punjabis—regard themselves as ethnically distinct. Some groups overlap the five categories: for instance, there are Punjabi Pathans as well as Hazarvi Pathans. Some smaller groups, such as the Brohis in Sindh and the Seraikis in Punjab, are also ethnically distinct.