Abstract: This study explored the effectiveness of motivational interviewing on academic procrastination in adolescents. To this end, an experimental design including pretest-posttest with a control group was employed. The research population consisted of all male students (488 in total) studying in the secondary high school in the Educational District 2 of Shiraz in the academic year 2017-2018. Using a multi-stage cluster sampling method, 30 high school students were randomly assigned to two groups (experimental and control), each with 15 students. The instrument used in this study to collect the data was Procrastination Questionnaire. A comparison of the mean scores and standard deviation of the research variables in the pre-test and post-test for the two groups indicated that procrastination scores of the treatment group on the posttest decreased significantly. However, there was no significant difference in the procrastination scores of the control group on the pretest and posttest. The results of covariance analysis on the postoperative scores suggested a significant difference between the experimental and control groups in terms of procrastination, thus the research hypothesis is confirmed. That is, the Individual Motivational Interviewing Therapy reduces students' procrastination. Therefore, it can be suggested motivational interviewing had a significant effect on procrastination (P <0.001). In addition, the result of ANOVA test on the procrastination scores in the follow-up stage showed that there was no significant difference between the treatment group students’ mean scores on the posttest and the follow-up test, which indicates the effectiveness of the motivational interviewing after two months. پرونده مقاله