The purpose of this study was to investigate the impact of using two visual while-reading strategies, knowledge-mapping (KM) and underlining, on the performance of intermediate students learning English as a Foreign Language (EFL) in multiple-choice reading comprehension tests. In doing so, 60 Iranian intermediate EFL students were selected from a larger population by means of a proficiency test. They were then divided into three groups: two experimental groups, i.e. KM and underlining, and one control group. First, the KM and underlining groups were taught how to use KM and underlining strategies respectively during reading. Then, all the subjects in the three groups took the same reading comprehension test. The results indicated that the underlining group scored the highest, followed by the KM group, with the control group performing the lowest. (Contains 2 tables.)