By creating patchy open areas rich in dead wood in the forest mosaic, windstorm is a major natural disturbance in temperate forests.This paper deals with the impact of the storm Lothar (in December 1999) on saproxylic beetle diversity in managed oak-hornbeam forests in the Brie region (France). Were there short-term gap effects and gap size effects on saproxylic beetle abundance, richness and assemblage composition in uncleared gaps in 2001? Do saproxylic assemblages differ in natural openings and in man-made fellings?Window flight traps were used to sample beetles moving through the air. Beetle assemblages were compared in 24 unlogged windthrow gaps (ranging from 0.1 to 3.3 ha in area), in 14 closed-forest paired controls and in 12 open stands (seed cuts and sapling stands). We sampled 33,799 saproxylic beetles (including 24,116 scolytids), that belong to 32 families or subfamilies and 185 species.Shortly after the disturbance, the abundance of saproxylic beetles did not vary in gaps compared to controls, but the species composition was significantly affected. The cumulative richness of saproxylic species (except scolytids) increased in the gaps. About 15 species (mainly sapro-xylophagous taxa) were characteristic of closed forest and strongly decreased in the gaps, whereas more than 30 species were typical of gaps (mainly pioneer xylophages dependant on fresh, sun-exposed dead wood; but also floricolous species or subcorticolous predators). Saproxylic species were more numerous in gaps than in open stands. Moreover, natural gaps exhibited more characteristic taxa than man-made fellings.Over the whole forest, gaps increase the gamma diversity. The maintenance of unlogged gaps and the partial salvaging of others are discussed as forest management opportunities.