Researchers have used semantic-mapping (SM) in different content-area instruction such as teacher education, social studies, chemistry, statistics, physiology, accounting, psychology, science, etc. However, very few researchers investigated the efficiency of computer-assisted semantic mapping (CASM) in improving students' understanding of medical texts. Moreover, few studies attempted to use CASM with students of different levels for text comprehension and recall and vocabulary improvement. Hence, this study aims at investigating the efficiency of CASM in improving ESP students' reading comprehension level and vocabulary knowledge. It also explores the effectiveness of CASM in enhancing students' ability for information retrieval. Finally, it documents students' attitudes towards using the SM technique.