Abstract: The advancement of Web Services (WS) and applications leads to the publication of numerous web services with similar features. Quality of Service (QoS) has become a key factor in selecting a right service from the huge collection of similar web services. Latterly, evolved semantic based approach OWL-S provides expressive functional description and discovery but it fails to support the QoS specifications in service description. To overcome the aforementioned issues, researchers present a novel framework called Trustworthy Semantic QoS based web service description and discovery (TSQoS). The proposed framework has two prominent features that differentiate it from other existing work in this research area. First, capability profile provides more expressive QoS aware functional descriptions through corresponding semantic ontologies that support new Capability Attribute Semantic Matchmaking (CASM) to return functionally matched web services. Second, to achieve automatic service discovery, adaptive trust-aware service selection is proposed based on user’s trust policy that implements a service executor. It computes actual QoS provided by the service from the objective values provided by QoS monitoring entities along with subjective evaluations (User feedback) provided by service consumers from their past experience. It also presents an efficient mechanism to determine the actual QoS by considering both published QoS description and computed eminence score. Thus, a service with high eminence score is returned as best service which can provide actual QoS required by the user. Finally, the experimental result shows that the proposed TSQoS based WSDD approach achieves increased precision and recall compared to existing QoS based WSDD approach.