||The Balkan Peninsula has rich biodiversity with a large number of endemic species; therefore, a part of its territory has been recognized as a World Biodiversity Hotspot. Despite nature conservation efforts and development of nature conservation networks in countries of the region, anthropogenic influence on natural and semi natural ecosystems is increasing. Moreover,new types of disturbance and pollution arise, and one of the more recent being artificial light at night (ALAN)which has serious consequences on reproduction, navigation, foraging, habitat selection, communication, trophic and social interactions of the biota. We have estimated the level of ecological light pollution in the strictprotected areas of the Republic of Serbia, the Republic of Bulgaria, and Montenegro using available GoogleEarth Pro tools, and the New World Atlas of Artificial Sky Brightness (2016) in the form of a kmz layer. The research has covered 13 National Parks, 11 Nature Parks and 55 Reserves. Our results showed widespread incursion of ALAN within strict protected areas in the studied region that has also been noted for some other countries and regions too. However, the level of light pollution is lower here, than in the most part of Continental Europe, and there are a few areas in each country where the night sky above National and Natural Parks is almost dark. These territories have a special value for nature conservation;therefore, it is important to save the dark night sky there.