Introduction: Students are daily exposed to a variety of assessment tasks in the classroom. It has long been recognized that students' perceptions of the assessment tasks may influence student academic achievement. The present study aimed at predicting academic achievement in mathematics from perceptions of the assessment tasks after controlling for gender and motivated learning strategies. Method: The participants were 232 students enrolled in grade 11 mathematics classes selected from public schools in Oman. Data were collected using the "Motivated Strategies for Learning Questionnaire" and "Perceptions of Assessment Tasks Inventory." Students' final grades earned in the subject were obtained from the school administration at the end of the semester. Results: A hierarchical multiple regression analysis showed that consultation and transparency were significantly related to mathematics achievement after controlling for gender and motivated learning strategies. Discussion: The findings contributed to the existing assessment literature by demonstrating the intersection between classroom assessment and self-regulation of learning and their effects on student achievement. Implications and recommendations for research and practice were discussed.