Summary. This study, based in south-east Sweden, shows how forest regrowth affects beetle species associated with old oaks. Beetle were trapped by pitfall and window traps placed in or near to the hollows in 90 old oaks in pasture woodland. The influence of a number of environmental parameters on the species richness of the beetles was assessed. A total of 120 saproxylic beetle species were identified, of which 40 were on the Swedish red list, including Xyletinus longitarsus, Ampedus cardinalis, Mycetochara humeralis and Prionychus ater. The number of beetles species trapped per tree varied from 7 to 34 (mean 20), and 52 species were found in four or fewer trees. This shows how important the range of conditions provided by a large number of veteran trees on a site is to support a high species richness of saproxylic beetles.