Purpose: This study aimed to explore the subjective theories of assessment held by preservice physical education teachers in a master’s program, focusing on each assessment literacy component. Method: Using a descriptive phenomenological approach, 11 master’s program preservice physical education teachers (three females, eight males) were purposefully and conveniently recruited in the study. Data sources were interviews, an online survey, instructor’s notes, and assessment samples. Deductive and inductive thematic analysis in NVivo 12 was employed, ensuring trustworthiness through data triangulation, peer debriefing, and member checking. Results: Four themes were generated across multiple data courses. The themes are (a) understanding of assessment purposes, (b) challenges in assessment implementation, (c) self-referenced assessment interpretation, and (d) critical perspectives on assessment data. Conclusion: The findings highlight the need for a comprehensive assessment education program that addresses all aspects of preservice physical education teachers’ subjective theories of assessment, enhancing their assessment literacy while considering their diverse backgrounds and stages of training.