New technology is a main determinant of the competitiveness of cities and regions nowadays. The availability of new technology reduces the amount of uncertainty companies deal with in their daily operations. In addition, new technology is a basis for the establishment of new companies and the restructuring of old ones. It has therefore a major influence on the development of urban and regional economies. An amazingly small amount of research has been done on the knowledge capacity of cities to date, i.e. their potentials to generate, store, transfer and use knowledge. This paper explores therefore the urban knowledge capacity theoretically and empirically. In the empirical part, the city of Delft in the Netherlands will serve as an example. In order to achieve a better insight into the knowledge capacity, a network approach will be adopted with an emphasis on knowledge stocks, flows, nodes, etc.