Ontologies provide a common conceptualization of the world to be shared across systems. Their reusability is assumed to be one of the main advantages of their application in the development of knowledge systems. Thus, libraries of reusable ontologies have already been built and made avai!able. This paper reports an attempt to reuse one ontology available for public use, and the practical developments associated with such attempt: the implementation of a practical ontology browser and the introduction of a reusability index. Although reusability is a goal difficult to achieve, it is concluded that, at this stage, properly assessing the reusability of existing ontologies is advisable since it complements and aids the task of building a technical ontology from scratch.