Studies on the relation of the diversity of wood-decaying fungi to elevation are scarce, and their results are not consistent. We found that the elevation gradient and structural characteristics of a Picea abies forest underlie changes in the species richness and composition of wood-decomposing fungi. The occurrence of macrofungal sporocarps on logs on the ground was recorded over 3 years in 12 study plots (total area 2.4 ha) on a mountain slope (1,220–1,335 m) in the Bohemian Forest, Czech Republic. The majority of species was more abundant in plots with a high mean volume of logs. The mean volume of logs was negatively related to elevation, which in turn had a negative influence on the occurrence of fungi. A negative relation of the high total volume of standing snags to the occurrence of fungi may be due to recent mortality caused by a bark beetle outbreak, albeit followed by the input of fresh logs that favoured a limited group of species. The diversity of fungi was also explained by the mean volumes of logs separated into decay classes. Numbers of red-listed species increased with the mean volume of logs and decreased with elevation. Large logs in later stages of decay provide essential habitat for the formation of sporocarps of red-listed species.