The diet of Barbastella barbastellus was investigated through analysis of droppings collected from three maternity roosts in Germany and Switzerland. The results showed a high dominance of moths (Lepidoptera), which accounted for 73–94% of the recovered items by volume. Flies (Diptera), ranging in size from blow flies (Calliphoridae) and large crane flies (Tipulidae) to small Nematocera, were the second most important prey items (4–17%). Prey types recovered also included small numbers of Trichoptera, Neuroptera, Homoptera, Hymenoptera, Coleoptera and spiders (Araneae). The diet of the barbastelle differs from that of most other bats in Europe in the predominance of moths and the corresponding virtual absence of dung beetles (Coleoptera; Scarabaeidae) and midges (Diptera; Chironpmidae). Conservation measures for barbastelles should therefore consider facilitation of the diversity and abundance of moths.