Urbanization is a process of land-use change that results in transformation of natural habitats and landscape structure and has been associated with the loss of biodiversity. Although different taxonomic groups are negatively affected by urbanization, little is known about the effects of urbanization on insectivorous bats. In addition, the influence of different urban green areas on bat activity and species richness has not been explored. The aim of this study was to assess whether landscape structure surrounding urban green areas influenced bat activity and species richness in total, as well as to assess differences in the response between functional groups. During summer 2014, I acoustically surveyed bats at 180 green areas in Vienna and quantified landscape structure at two spatial scales. My results showed that bats responded to landscape structure in diverse ways depending on the scale of analysis. Therefore, response assessments of a high mobile order like bats on land-use changes has to be done at least at two scales. Although my study showed differences in the response of bats based on morphological and behavioral traits of bat species, certain landscape characteristics seem to be important for most groups and management efforts need to take these findings into consideration. Bat activity of most functional groups was favored by size and shape of green areas. Also, a high diverse landscape and high intermixture of land-use strongly influenced species richness and bat activity. Thus, large and simply shaped green areas and a diverse and intermixed landscape are important to mitigate the impact of urbanization on bats. My assessment of the influence of building height gave first indications that building height affected bat activity and species richness. Thus, it is important for bats to ensure the possibility to exploit the urban landscape with low energy costs by maintaining intermixed building heights within highly urbanized areas.