This study was an attempt to investigate the effect of two types of learning, competitive and cooperative, on the reading comprehension of introvert and extrovert EFL learners. To this end, 120 learners studying at Marefat English Language Institute in Tehran, Iran were selected, after taking a Preliminary English Test (PET), to participate in this quasi-experimental research. The participants also answered the Eysenck Personality Inventory (EPI) to categorize them into two personality types of introverts and extroverts. Therefore, there were four subgroups: 30 introverts and 30 extroverts undergoing the cooperative learning treatment, and 30 introverts and 30 extroverts experiencing the competitive learning treatment. The reading part of the PET was administered as the posttest of the study after each group was exposed to the treatment for 18 sessions in seven weeks. A two-way ANOVA was run on the collected data in the posttest of four groups. The results revealed that while learners generally outperformed in the competitive setting compared to the cooperative one, the extrovert was better off receiving cooperative instruction. Moreover, introverts excelled extroverts in the competitive group. However, there was no difference between the two personality groups in the cooperative situation.