Purpose: The research aimed to investigate the factors underpinning academic optimism and its impact on the academic achievement of students in agriculture vocational schools. Methodology: It was carried out among the students of the agriculture vocational schools in Tehran province, Iran (N = 435). A sample of 158 students was taken by the stratified random sampling with proportional assignment. The measurement instrument was standard questionnaires whose validity was determined by content and construct validity. To estimate the reliability of the questionnaires, a pilot study was conducted on 30 individuals outside the sample, and Cronbach's alpha and composite reliability were measured. Findings: The results showed that academic engagement and academic emotions had significant impacts on students' academic optimism. The effect of academic optimism was also found to be significant on students' academic achievement. It is concluded that academic optimism and its components, both at the personal and school level, play an essential role in students' academic achievement. Practical implications: The Education Organization should develop plans for improving teachers' and students' academic optimism and enhancing their motivation for academic achievement. Theoretical implications: The study enriches the existing literature on academic achievement by emphasizing the importance of academic optimism in the process of agricultural technical and vocational education. It also highlights the potential of psychological components to motivate students' academic optimism in the process of academic achievement. Principals and educators are suggested to develop optimistic beliefs in themselves and create an optimistic, active, and vibrant school climate, thereby providing the conditions for the growth of academic optimism among students. Originality/value: The paper provides insight for education organizations to recognize the barriers to the improvement of the students' academic achievement in the agriculture vocational schools.