Towards the end of the 20^th century the Karkonosze Mountains in southwestern Poland were characterized by vast swathes of dead and dying spruce forests whose condition at the time was described as an ecological disaster. Wood-decaying fungi play an important role in global carbon and nitrogen circulation by promoting the bioconversion of organic matter. The aim of our study was to determine the composition of the fungal community in the ‘post-disturbance’ dead spruce wood in relation to the season and degree of wood decay in the Karkonosze Mountains. Mycological analyses were carried out in 2015 and 2016 in the submontane and mountain forest zone, as well as in the subalpine zone of Karkonoski National Park (KNP). The findings reveal that the prevalent fungi colonising the internal tissues of dead wood belonged to the genus Trichoderma. Their proportion in the material under study increased in advanced stages of wood decay. However, the mycobiota of dead spruce at lower levels of decay were characterized by the highest diversity. The analysis also showed seasonal variations in the composition of the fungal communities colonizing dead wood.