In managed French oak-hornbeam forests storm-damaged in 1999, saproxylic beetles were sampled by window-flight traps in 2001. We observed a strong differentiation but only a slight increase in richness of saproxylic assemblage in gaps compared with undisturbed stands. Gap size effect was non linear. Surrounding landscape and local tree species density influenced some species. Saproxylic communities were also distinct in gaps and in fellings. Because of the richness of mid- and large-sized gaps and their faunistic dissimilarity with other open stands and closed-canopy controls, retaining uncleared gaps above 0.5ha in size may enhance saproxylic gamma diversity in forests.