We examined the effects of teachers' classroom assessment practices and students' perceptions of assessment tasks on students' academic self-efficacy beliefs as 1 dimension of student academic motivation. Participants (N = 1,457) were students sourced from 99 classrooms of public secondary schools in Oman. Results of multilevel analysis showed that student academic self-efficacy beliefs were significantly and positively influenced by students' perceptions of the assessment tasks. Specifically, congruence with planned learning, authenticity, transparency, and diversity all had significant positive influences on self-efficacy beliefs, as did frequent communication by the teacher about the assessment with students and teachers' frequent use of nonachievement grading factors. Implications are discussed for classroom practices and research related to classroom assessment.Keywords: classroom assessment practices, student perceptions, educational assessment, academic self-efficacy.Classroom assessment, that is, the process of obtaining information about students' performance on assessment tasks, is one of the main responsibilities of teachers. Teachers use a range of assessment methods and tools to determine how well students are achieving the intended learning outcomes (Gronlund, 2006). In numerous literature reviews scholars have asserted the power of classroom SOCIAL