In this paper, we present a novel approach, named RS2D, to risk driven semantic service query routing in unstructured, so called pure P2P networks. Following the RS2D protocol, each peer dynamically learns about the query answering behavior of its direct neighbours. without prior knowledge on the semantic overlay. The decision to whom to forward a given service request is then driven by the estimated mixed individual Bayes? conditional risk of routing failure in terms of both semantic loss and high communication costs. The results of our experimental evaluation of retrieval performance and robustness show that RS2D top performs compared to other relevant systems.