Abstract Introduction Clinical skills are fundamental to medical school curriculums and typically introduced within the preclinical years. In their experiential learning, students' self‐efficacy, or the belief in their ability to succeed, is an important factor in influencing clinical skill mastery. Reflection is thought to affect self‐efficacy; however, its exact impacts remain largely unexplored within published literature. This mixed methods study investigated whether preclinical students' engagement with reflection affected self‐efficacy for clinical skills. Methods Two hundred seventy‐three of the 289 preclinical medical students who were invited to participate responded to this 2022 study. We used validated questionnaires to measure engagement with reflection and perceived self‐efficacy for clinical skills, conducting hierarchical multiple linear regression for analysis. Thirteen students participated in semi‐structured interviews and focus groups, which were analysed via thematic analysis. Results While statistical analysis showed no significant effects of engaging with reflection on clinical skill self‐efficacy, thematic analysis suggested that students perceived the opposite. The themes through which reflection affected self‐efficacy were by ‘evaluation of performances’ against expected outcomes, ‘familiarisation and understanding of skills’, by ‘transforming personal mindsets’ and allowing students to ‘connect to their emotions’. Conclusion This study suggests that engaging with reflection can positively or negatively affect self‐efficacy for clinical skills, depending on students' attitudes towards reflective practice. Solely engaging with reflection is insufficient to alter self‐efficacy beliefs and should be considered alongside personal factors including the individual's mindset and perceived need for reflection. The medical educator's role in facilitating reflection is important, enabling students to reap the benefits of this practice.