Based on social cognitive theory, this study focused on how self-efficacy beliefs were related to assessment practices among experienced university teachers. The data consisted of 16 thematic interviews of university teachers from various faculties who had received awards of excellence in teaching. The thematic interviews were content analyzed both inductively and deductively. Academics' self-efficacy experiences were related in four assessment modes: assessment in general, diagnostic assessment, formative assessment and summative assessment. Sources of self-efficacy experience were identified by mastery experience, vicarious experience, social persuasions and physiological and affective states. The mastery experience was the most common source of self-efficacy in assessment practice, and for experienced teachers, fairness was the prominent feature in assessment.