As human linguistic practice reveals, accessing to concepts through natural language is the implicit pathway for enabling mutual comprehension and effective meaning negotiation between agents in a community. We need more than a shared dictionary, in order to exchange knowledge: we need to share the “conceptual models underlying the lexicon”, namely ontologies. These remarks become even more crucial when focusing on human-computer interaction. In this context, computational ontologies and human-language technologies converge in the task of providing the semantic description of knowledge contents (e.g. multimedia, Web resources, etc.): underlying intended models need to be made explicit in order to become accessible by artificial agents and sharable with humans. According to this picture, 1) computational lexicons, whose aim is to make lexical-content machine-understandable, constitute a fundamental component to foster the linguistic access to any knowledge content; 2) computational ontologies, on the other side, are necessary to capture the logical structure of those knowledge contents: both contribute to dig out the basic elements of a given semantic space (domain-dependent or general), characterizing the different relations holding among them. The OntoLex workshop is addressed to researchers and practitioners from a variety of backgrounds that are concerned with the representation, acquisition and use of lexical knowledge in semantic annotation, ontology-based approaches to information extraction, ontology learning, ontology matching, ontology population, etc.