The importance of deadwood (DW) in forest ecosystems is widely recognized today. Deadwood is used as a proxy indicator for biodiversity conservation and sustainable management of forests. This research aims to determine the amount and spatial distribution of DW (standing dead trees, stumps, and coarse woody debris) and characterize the changes with few selected parameters in an unmanaged forest reserve of Köprülü Canyon National Park (NP). The data were collected from 387 temporary sample plots with different stand characteristics such as stand age, crown closure, site index, and density, and site parameters like elevation, aspect, slope, and distance to settlement areas of Calabrian pine (Pinus brutia Ten.)-dominated forests. The mean volume of DW was 3.8 m/ha which was 2.4% of the total standing living volume. The volume of standing DW was 0.5 m/ha (13.2%), that of stumps was 0.2 m/ha (5.3%), and that of down DW was 3.1 m/ha (81.5%). Statistically, positive correlation was found between the volume of DW and that of living trees, crown closure, altitude (p < 0.01), and stand age (p < 0.05). However, negative correlation was found between the number of understory trees (p < 0.01) and DW. The results obtained from Calabrian pine (P. brutia Ten.) can be used as reference values for managed forests and can contribute to set the rules in deciding the appropriate level of DW in particularly biodiversity integrated forest management planning.