This study explored whether hypermedia annotation presentation in different locations of the text facilitates EFL vocabulary acquisition and reading comprehension. It also examined participants' preferences for the location of hypermedia-annotated text (at the end of the text, in the margin, at the bottom of the screen, or in a pop-up window). Data were collected from 80 intermediate adult EFL learners who read annotated texts and received support in different conditions of hypermedia annotations. A survey of prior knowledge was carried out, followed by vocabulary and reading comprehension tests, and a questionnaire. Results indicated that students who had access to hypermedia annotations outperformed their peers who used traditional glosses listed at the end of the text. There was also a positive impact for texts with hypermedia annotations located in the margin of the text. Learners also preferred hypermedia annotation presentation in the margin. Finally, no relationship was found between participants' preferences and their level of achievement. (Contains 1 figure and 4 tables.)