Information and communication technologies (ICTs) are relevant to almost every aspect of our lives and initiate / accelerate crucial processes of transformation. Against this background, ICTs are defined and their importance for urban innovation / competitive capacity is explained. Thereafter selected theoretical approaches are presented, which refer to companies' decisions on the location of their business activi-ties. One example for that are 'spill-over effects': They describe advantages, which result from spatial proximity of research facilities / educational institutions and innovative companies. ICTs have great significance for the City of Vienna. This is also evident in relatively high value creation / employment effects. The political community and several tools to promote business try to enhance ICTs. This involves the definition of cluster initiatives and major areas of expertise. The Vienna Business Agency, for example, distinguishes between the topic areas 'Mobile Apps', 'Big Data - Open Data', 'Cloud Computing', 'E-Government', 'Emerging Technologies', 'User Centered Design' , 'IT-Security' and 'E-Health', which are declared as highly important for Vienna's economy. This thesis focuses on the localised system of production, which is constituted by innovative ICT-companies' daily work. On this basis, the structure of the branch and spatial distribution of essential topic areas are compared. A critical reflection against the background of several regional policies forms the conclusion of this Thesis.