This study intended to unveil the impact of incorporation of positive psychology theory into English instructions on the preference for anxiety-reducing strategies among Iranian EFL learners. The participants consisted of 60 EFL learners, from Safir Institute, Tehran, Iran, at the intermediate level, who were selected out of 90 EFL learners selected on convenience sampling basis. The 60 learners selected on the basis of their scores from an Oxford Placement Test (OPT), given to the 90 learners, were split into two equal 30-member groups. Both groups were given the language anxiety reducing strategies (LARS) questionnaire as pretest. Then, positive psychology-based instructions were provided to the experimental group drawing on five types of positive psychology-based instruction techniques for 20 sessions. These five instruction techniques included gratitude, optimistic intervention, positive affirmations, savouring, and strength-building measures. The control group received no intervention concerning positive psychology, and learners followed the conventional syllabus of the language school. After the treatment, the two groups took the LARS questionnaire as post-test. The results of ANCOVA indicated that teaching positive psychology techniques significantly increased anxiety-reducing strategies preference among Iranian EFL learners. تفاصيل المقالة