The Coleoptera of the Botanical Garden in Bonn, Germany. Between May 1991 and August 1993 the beetle fauna of the Botanic Garden of the University of Bonn (Germany) was studied. The park is situated in the city, and consists of woods, open fields, and a pond to a total area of 6.5 ha. The distance to natural habitats is at least 800 m. Beetles were collected by hand, sweep netting, several types of traps (pitfall, flight interception, carrion, dung), and car netting. 8401 beetles of 603 species were collected. Several compost dwelling species rarely found in natural habitats were recorded. The fauna lacks many species of wingless ground beetles, which are probably unable to reach the garden due to high traffic on the surrounding streets. Cerambycidae and Buprestidae as well as tree dwelling Curculionidae which are rich in species and abundant in natural habitats outside the city, were rare and poor in species in the garden. The development of the larvae of these beetle groups living in dead wood or in the soil below the host plants is probably restricted by gardening. Medium body size of the beetle fauna is significantly lower than in natural habitats. The lack of large beetles is probably a result of small habitat size. Despite these restrictions, compared to other studies in city parks and gardens, the beetle fauna of the Botanic Garden in Bonn is very diverse and rich in species.