Islamabad is a place.
Islamabad ( [ ɪzˈlɑːməˌbɑːd ] [ , , [ ɪsˌlɑːmɑˈbɑːd̪ ] ) is the capital city of Pakistan located within the federal Islamabad Capital Territory . With a population of two million , it is the 10th largest city of Pakistan , while the larger Islamabad-Rawalpindi metropolitan area is the third largest in Pakistan with a population exceeding five million . Islamabad was built during the 1960s to replace Karachi as Pakistan 's capital . Islamabad is a beta - world city ; it is categorised as very high on the Human Development Index , the highest in the country . The city has the highest cost of living in Pakistan , and its population is dominated by middle and upper middle class citizens .