Abstract. Recently, more and more web services are being made available and their use can potentially highly increase cooperation in P2P systems, where different partners intend to share and exchange digital resources. A major concern, in this framework, is related to the development of semantic driven techniques for description and organization of available services in semantic communities for discovery purposes. We propose an ontology-based Semantic Driven Service Discovery approach in P2P systems, where peers are organized in a semantic community to support effective automation of service discovery. In the approach ontologies are exploited both to improve precision and recall of search results by means of an innovative service matchmaking strategy and to organize services in the community by means of intra-peer and inter-peer semantic links. Some experimental results are briefly discussed.