This study examined the effectiveness of an integrative intervention combining motivational interviewing and metacognitive skills training on academic goal orientation and school engagement among twelfth-grade students. Given the declining motivation and engagement observed in final-year secondary students, particularly in high-stakes educational contexts, interventions addressing both motivational and cognitive processes are critically needed. A quasi-experimental design with pretest, posttest, and two-month follow-up assessments was employed with a control group. The statistical population comprised all female twelfth-grade students in Shahrekord, Iran, during the 2025 academic year, from which 40 participants were selected through convenience sampling and randomly assigned to experimental (n=20) and control (n=20) groups. The experimental group received 12 weekly 60-minute sessions of the integrative intervention, while the control group received no intervention. Data were collected using Bouffard's Academic Goal Orientation Questionnaire and Wang et al.'s School Engagement Scale, and analyzed through repeated measures ANOVA. Results demonstrated significant increases in both academic goal orientation (η²=0.53, p<0.001) and school engagement (η²=0.75, p<0.001) in the experimental group compared to controls, with effects maintained at two-month follow-up. The significant Group × Time interactions confirmed differential change patterns between groups. These findings suggest that the synergistic combination of motivational interviewing—which addresses the "why" of learning through enhancing intrinsic motivation, autonomy, and commitment—and metacognitive skills training—which addresses the "how" of learning through planning, monitoring, and self-regulation strategies—creates a self-reinforcing cycle of motivation and skill development. The sustained intervention effects indicate that equipping students with both motivational resources and practical learning strategies facilitates durable changes in academic attitudes and behaviors. This integrative approach offers a promising evidence-based strategy for school counselors and educational psychologists seeking to enhance academic motivation, prevent disengagement, and support student success during the critical transition period of upper secondary education. However, findings should be interpreted considering limitations including the relatively small sample size, gender-restricted population, reliance on self-report measures, and two-month follow-up period. Future research should examine this intervention with diverse populations, extended follow-up durations, and objective academic outcome measures to further establish its efficacy and generalizability