Introduction: In contemporary information societies, reading digital text has become pervasive. One of the most distinctive features of digital texts is their internal connections via hyperlinks, resulting in non-linear hypertexts. Hypertext structure and previous knowledge affect navigation and comprehension of digital expository texts. From the Cognitive Load framework, working memory capacity would have a role in supporting decisions about navigation, and in situation model construction for comprehension. The present study assessed text structure, previous domain knowledge, and working memory capacity effects on comprehension and navigation of digital expository texts. Method: Fifty-six participants completed a working memory capacity measure, read four digital texts and answered questions about them. Hypertext structure (hierarchical vs. network) and previous thematic knowledge (high vs. low) were manipulated in a within-subjects design. Navigation behavior was indexed taking into account total time spent on each text, total number of pages per text, number of returns to the initial page, and number of nonlinear links clicked. Results: High previous knowledge, and high working memory capacity, led to better comprehension. Participants who read under network interfaces followed less structured navigation paths than those who read hierarchically organized interfaces. On the other hand, high previous knowledge texts led to more pages visited, more non-linear jumps in reading, and more returns to the overview in the Home page in the network condition. Also, total time spent on each text was longer for high working memory participants reading high previous knowledge texts. Discussion: Overall, this pattern of results adds to the literature about the beneficial effects promoted by hierarchical interfaces and concept maps; and the disorientation effects network hypertexts have for low domain knowledge students. On the other hand, given good previous knowledge and high working memory, a more variable pattern of navigation would help readers engage in more active reading processes.