Afghanistan according to its constitution is Islamic Republic; About 99% of the Afghanistan citizens practice Islam. 

Sunni Islam makes up 80%, Shiya Islam is 19%, Hindus sre 0.6% and 0.4% are Sikhs of the total population of Afghanistan.

Before the 7th century the territory of Afghanistan was inhabited by people of multi-religion as Zoroastrians, Hindus, Buddists, Christians and Jews. 

Islam was brought to Afghanistan during the Arab invasion in the middle of the 7th century.