Case Based Reasoning (CBR) is a problem-solving paradigm that uses knowledge of relevant past experiences (cases) to interpret or solve new problems. An evolvement to this paradigm is ontology-based CBR, an approach that combines, in the form of formal ontologies, case specific knowledge with domain one in order to improve the effectiveness of the CBR process. This effectiveness is further improved if ontology-based CBR systems are able to utilize knowledge that is vague or imprecise; to that end, we present in this paper a novel CBR approach that manages and utilizes imprecise knowledge through the integration of Fuzzy Algebra in the ontology- based CBR paradigm. The approach has been applied in real life and constitutes the core of a portal that provides the public with intelligent access to knowledge assets.