Procrastination is a prevalent behavior affecting all life aspects, especially educational fields. Educational procrastination is defined as unnecessary delay for doing assignments. Personality traits are very important in explaining procrastination. This study aimed to investigate the structural model of academic procrastination based on personality traits by student's educational motivation. Materials and Methods: In the current cross-sectional descriptive-analytical study, the participants consisted of 400 students (171 boys and 231 girls) of secondary high school in Bojnord City, Iran in 2017-2018 academic year. The students were selected by the multistep random clustering sampling method from 3 girls' high schools and 3 boys' high schools (3 classes from each high school) from the north, south, east and west districts of the city. The relevant data were gathered by Academic Procrastination Scale, personality traits, and educational motivation questionnaires. Data analysis was done by structural equation modeling in LISREL V. 8.80. Results: According to model fitting, direct effect of neuroticism conscientiousness and educational motivation upon academic procrastination was significant (P˂0.05). Also, the standard effects of neuroticism and conscientiousness upon educational procrastination (by educational motivation) were significant (P˂0.05). Conclusion: According to the results, anxiety management training for neurotic persons, as well as improving agreeableness rate will result in an increase in educational motivation and, in turn, a decrease in academic procrastination.