With the growing popularity of Web services, a general QoS support for Web services will play an important role for the success of this emerging technology. Unfortunately, current Web service environments do not offer comprehensive QoS support. In this paper, we present an approach that does not only enable the QoS integration in Web services, but also the selection of appropriate services based on QoS requirements regarding server and network performance as well as the mapping of QoS requirements onto the underlying QoS aware network at runtime.