In a description of language, Ellis (1994) claims that "the bedrock of L2 is its vocabulary" (p. 11); while for Lewis (1993), language consists of "grammaticalized lexis", not "lexicalized grammar", and Nation (2001) adds that attention to vocabulary is unavoidable. This status of vocabulary determines its pervasiveness and implies the need for attention as claimed by Meara (1980). In second and foreign language teaching and learning, instruction is an important contributor in the development and consolidation of vocabulary knowledge while Computer-Assisted Language Learning has been described as facilitative in mediating instruction and improving learner independence (Chapelle 1998, 2001; Warschauer, 1998).The present study investigates narrative comprehension, immediate and delayed vocabulary retention as a result of implicit and explicit teaching and learning of vocabulary (Hunt & Beglar, 2005), with a hypertext reading task. Many researchers support that enhanced vocabulary activities and reading for meaning affect vocabulary acquisition (Krashen, 1989, Zahar et al., 2001; Paribakht & Wesche, 1997; Lee & VanPatten, 2003). For others, the degree of involvement in the processing and the noticed properties of words determine the degree of retention (Groot, 2000; Smith, 2004).Seventy-eight fourth-semester students of French as a foreign language from six classes at an American university participated in the study. They were randomly assigned to either the implicit or the explicit conditions, and received differential treatments. The subjects read the same enhanced electronic text with permanently highlighted target items in the explicit condition, and temporarily highlighted target items in the implicit condition. The target items were hyperlinked to the same textual, auditory, and graphic enhancements. The study also makes an overview of the effect of the motivation type on the subjects' performance levels.The statistical analyses reveal both strengths and weaknesses in the two modalities with regards to immediate and delayed retention; as one of the modalities favors immediate gain and the other longer-term retention. It is thus suggested that both modalities can be jointly implemented in a Computer-Assisted Teaching and Learning condition in order to achieve higher learning outcomes. The combination may favor the dual improvement in gain and retention in the learning process.