Distributed applications are rapidly converging towards the adoption of a computing paradigm based on SOAs (service-oriented architectures), according to which an application results from the composition of a set of services in execution on networked server hosts. In this context, in order to provide SOA-based applications with high levels of QoS (quality of service), service providers may employ P2P (peer-to- peer) networks to bring applications closer to their consumers, overcoming slow backbone paths, network congestions and physical latencies. The ability to efficiently carry out service discovery activities is a key issue for effectively managing the QoS of SOA-based P2P applications. To this purpose, this paper introduces QSHARE, an approach for the QoS-enabled description and discovery of services in SOA-based P2P applications. The proposed approach introduces a novel peer architecture that makes use of QoS-enabled service descriptions and its effectiveness is shown within the context of a model-driven framework for managing the QoS of SOA-based P2P applications.