The current article was an attempt to investigate the effect of semantic mapping strategy instruction on reading comprehension performance of EFL learners. To this end, thirty homogeneous Iranian intermediate EFL learners attending a language school in Bonab, Iran, were randomly assigned to two groups, one as the experimental and the other as the control. The experimental group received instruction through semantic mapping strategy while the control one received conventional instruction by the same instructor. The study employed pre-test post-test control group design. After two months, on-line and off-line post-tests were administered for experimental and control groups. Analysis of gathered data from post-tests by using independent samples t-test and one-way ANOVA indicated that semantic mapping instruction promotes reading comprehension of expository texts. Furthermore, it was found that certain types of semantic maps were more effective not only on reading comprehension performance but also on faster reaction time
