Despite the problems presented by lexical errors in second language (L2) communication, most computer assisted language learning (CALL) programs tend to focus on the acquisition of grammar points rather than on the development of the L2 lexicon. In addition, CALL vocabulary tasks are typically limited in scope and mechanical in nature, covering mostly basic lexical meanings and ignoring many implications of language-related research that points out the need to focus on the layers of meanings associated with lexical items in various cultural contexts. This article brings together findings from research in various research fields related to Spanish SLA (e.g., cognitive psychology, psycholinguistics, and sociolinguistics) in order to propose 10 design features (DFs) of CALL software that would apply these insights to the creation of various types of computer-based lexical acquisition activities. As the authors propose these principles, they review several examples of Spanish CALL lexical materials in terms of their application of current theory (SLA and related fields) to practice (the design of the software activities to teach vocabulary). To conclude, the authors discuss logistical barriers that complicate and inhibit the application of theory and empirical research to practice in the creation of Spanish CALL lexical materials. (Contains 15 notes.)