Studies on the processing, functional, and social distribution of spoken and signed languages suggest partial overlaps between the mental lexicon of deaf and hearers. However, factors such as ontogenetic development, language acquisition conditions, the development of deaf culture, and the lexical repertoire available in each language suggest important differences. The aim was to explore the semantic networks of the conceptual domains of space and time in the Uruguayan deaf signers' population and Spanish hearers. 60 participants carried out a word association task in their respective languages and with semantically equivalent lexical items. Both groups showed an important formal similarity between their semantic networks. Mainly, a categorical-semantic analysis showed a bias of the hearers to taxonomic and introspective semantic relationships. In contrast, the deaf showed a bias toward situational semantic relationships and entities. These findings suggest differences in the concrete / abstract thinking between both populations when organizing their mental lexicon.