Software systems are becoming increasingly complex, demanding for more computational resources and better software development methodologies. The software engineer and the CASE tool must work like a team. For this to happen, the CASE tool must be able to understand the user, and to provide new functionalities, such as flexible retrieval of old designs. We think that Case-Based Reasoning can provide a reasoning framework capable of meeting these demands. One important task that a CASE tool based on Case-Based Reasoning can perform adequately, is the retrieval of relevant designs. These designs can be stored in a case library, central to the software development company, thus enabling knowledge sharing through out the company. In this paper we present an approach to case-based retrieval of software designs, and experimental results achieved with this approach.