The goal of the current study is to determine the effect of THIEVES strategy on ESP university students' reading comprehension and inquiry learning skills. It was assumed that students received training on THIEVES strategy would perform better on reading comprehension and inquiry learning skills than their counterparts in the control group. The tools -designed by the researchers- that were used for reaching statistical results included: (reading skills checklist, inquiry learning skills checklist, reading comprehension test and inquiry learning test). Findings showed that THIEVES strategy made a significant difference in enhancing reading comprehension and inquiry learning skills of the experimental group.