In this paper, the Arabic lexicon has been investigated in the context of relational database theory. A feature analysis of lexical entities has been carried out which shows that lexical attributes can be classified into five categories comprising nineteen attributes, including form attributes, morphological attributes, functional attributes, meaning attributes, and referential attributes. Based on this analysis, eleven database relations have been identified which form the backbone of an Arabic lexical database, including: words, roots, forms, infinitives, verbs, nouns, plurals, particles, meanings, lexical functions, and cross-references. The design ideas discussed in this paper were tested using a sample of lexical items selected from a modern printed dictionary. The results of developing an experimental lexical database indicate that the relational approach provides an efficient method for storing and retrieving Arabic lexical information. It should be mentioned, however, that several problems were encountered when the printed data was translated into a database form. Some of these problems are inherent in the Arabic lexicon itself, while others are due to the way by which lexical information is presented by paper-based dictionaries.