Rugova's spokesman, Muhamet Hamiti, said the president died shortly before midday in his residence in the region's capital, Pristina.
Rugova, a chain-smoker, was diagnosed with lung cancer in September 2005.
Rugova had been at the forefront of ethnic Albanian demands for independence from Serbia since the early 1990s, when he led a nonviolent movement against the policies of Slobodan Milosevic, the then president of Yugoslavia.
His death comes at a sensitive time for Kosovo, which is about to start negotiations about whether it should remain part of Serbia or become an independent state.
The province's ethnic Albanian majority wants full independence, but Serbs want Kosovo to remain part of Serbia- Montenegro, the union that replaced Yugoslavia.
The first formal UN-mediated talks between delegations from Kosovo and Serbia were due to take place on 25 January in Vienna.
However, the UN's special envoy to Kosovo, Martti Ahtisaari, has postponed the talks until February due to the official period of mourning that will now be observed in Kosovo for Rugova.
(compiled from agency reports)
THE WORLD'S NEWEST NATION? The region of Kosovo has a population of more than 2 million, some 90 percent of whom are ethnic Albanians. It was one of the poorest regions in the former Yugoslavia, but has considerable mineral wealth and an enterprising population, many of whom work abroad but keep close contact with Kosovo. All ethnic Albanian political parties seek independence on the principles of self-determination and majority rule. They feel that Serbia lost its historically based claim to what was its autonomous province under the 1974 constitution by revoking that autonomy in the late 1980s and then conducting a crackdown in 1999 that forced some 850,000 people to flee their homes.
Since NATO's intervention that year to stop the expulsions, Kosovo has been under a UN administration (UNMIK). The UN has begun to gradually transfer functions to elected Kosovar institutions. The primary Serbian concerns are physical safety for the local Serbian minority, a secure return for the tens of thousands of Serbian displaced persons, and protection for historic Serbian religious buildings. The main problems affecting all Kosovars, however, are economic. Until Kosovo's final status is clarified and new legislation passed and enforced, it will not be able to attract the investment it needs to provide jobs for its population, which is one of the youngest and fastest growing in Europe. Prosperity is widely seen as the key to political stability and interethnic coexistence in Kosovo, as is the case in much of Southeastern Europe.
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