Objectives: This study was carried with the purpose of evaluating the effectiveness of self-regulation strategy training on procrastination, academic achievement, and happiness of 1st grade high school male and female students. Methods: It is a quasi-experimental research with a pretest-posttest design involving a control group. Sixty students were selected by means of multistage cluster sampling plan and randomly grouped in 4 groups of 15. Research instrument consisted of Solomon and Rothblum Academic Delay, Oxford Happiness, and Standard Academic Achievement Questionnaire. Test group received 8 self-regulation training sessions of 45-minute duration each. Results: Results revealed that self-regulation training has a meaningful effect on dependent variables (P < 0.001). In the presented model, "gender", "time and group", "interactive effect of gender and group", and "interactive effect of group and time" were meaningful, as opposed to the "interactive effect of gender and time" and "interactive effect of gender, group, and time" which lacked any significance. Conclusions: Results of LSD post hoc test showed no meaningful difference between the mean happiness, procrastination, and academic achievement scores of experimental and control groups in the pretest stage. However, in the posttest and follow-up stage, the mean scores of the two groups differed significantly.