This systematic review examines how preservice teachers' (PSTs) domain-specific epistemological beliefs (EB) are studied and understood within initial teacher education (ITE) with attention to theoretical, contextual, and methodological aspects. Findings from 24 empirical studies published up to 2024 were synthesized. The review analyzed theoretical frameworks, research designs, and tools commonly used to explore PSTs' EB across specific domains. Cross-study evaluations are challenging due to the ambiguity created by the lack of justification for framework selection, although the variety of theoretical lenses enhances the field. Similarly, methodological preferences such as the dominance of quantitative and cross-sectional studies using closed questionnaires offer generalizable insights but limit the depth of understanding regarding EB development. Nevertheless, specific contexts of ITE were identified as catalysts for developing EB, and some EB were seen as key predictors of student-centered teaching practices. The field shows theoretical and methodological fragmentation but offers insights into how ITE might influence EB. Bridging current gaps is crucial for a deeper understanding of PSTs' conceptions of knowledge and learning. Recommendations include adopting longitudinal designs, clarifying theoretical foundations, and involving broader ITE stakeholders such as mentors and policymakers whose beliefs also shape teacher education.