Abstract: The Great Capricorn Beetle, Cerambyx cerdo L., is a saproxylic insect highly dependent on oak trees. Presence of this species was reported in the Natura 2000 site “Gravine di Matera” (code IT9220135), a 7000-hectares protected area in southern Italy. From June to early July 2019, we conducted the first monitoring study of this species, assessing the population size and habitat preference. Baited traps were positioned on trees of different oak species present in the area in order to assess the population size of the Great Capricorn beetle across the study area. Overall, 78 beetles (37 females, 41 males) were caught during 16 days of sampling. Highest densities of C. cerdo were encountered on downy oak trees (Quercus pubescens Willd.) and tree size appeared to be positively correlated with the number of C. cerdo individuals captured on the tree. This demonstrates the importance of the presence of large veteran trees for the conservation of this species.