As an attempt to shed more light on the relationship between critical thinking skills and the students’ performance on EFL learning activities, the present study investigated the relationship between critical thinking skills of Iranian EFL young learners and their performance on textbook activities. To this end, 120 female students between 9 to 12 years old filled out the Persian version of critical thinking skills questionnaire (Naieni, 2005). Besides, the participants answered the selected activities from second language English series such as Family and Friends, Let’s go, and Hip Hip Hooray textbook series. The findings of the study revealed that critical thinking skills and EFL young learners’ performance on the activities were significantly correlated for the students of various groups of language proficiencies. More specifically, it was revealed that there was not any statistically significant relationship between beginner and intermediate learners’ critical thinking skills and their performances on the textbook activities, while there was a significant correlation between advanced learners’ performances and their critical thinking skills. In addition, there was a significant difference between the performances of high and low critical thinkers in the advanced group. However, there was not any significant difference between high and low critical thinkers in beginner and intermediate groups. Finally, the discussion of the findings and implications ensues.
