Bike sharing systems, like the Viennese Citybike, are sustainable, active and easily accessible public transport systems. Through the promoting of bicycle traffic, these systems contribute to a sustainable urban development. Due to the growing, global demand on bike-sharing systems and the diverse political and planning objectives, which are pursued through the implementation of such systems, a huge research interest is given. The current paper deals with the access and egress behaviour at Citybike Vienna stations. First the basic terms and concepts of Bike-Sharing systems are explained and on this basis the existing System Citybike Wien is analysed. Afterwards the data collected via on-site user surveys which contains inter alia personal user data, reasons for Citybike usage and trip chains information is presented. Finally the trip chains and path lengths are analysed and the range and catchment area of each station get derived. The basic hypothesis is that there is a difference in access and egress behaviour, depending on the position of the Citybike station in relation to the next station of public transport and its quality of service. Concerning the catchment area this hypothesis is validated.