OBJECTIVES: Exploration of influencing factors and promotion strategies for self-directed learning (SDL) is a current research hotspot. However, there is a dearth of relevant research among medical trainees. The objective of the present study was to explore the perceptions of SDL among medical trainees, while also identifying the multidimensional factors associated with SDL and potential facilitating strategies from the perspective of medical trainees. DESIGN: This multicentre qualitative study used focus group discussions to gather insights into SDL, analysed through thematic analysis. NVivo V.12 was used for efficient data management and processing. SETTING: Four focus group discussions were held at three large tertiary hospitals in mainland China from December 2022 to July 2023. PARTICIPANTS: This study used purposive sampling to recruit eligible participants from the selected hospitals, primarily through instructor recommendations. Recruitment was further supported by snowball sampling, where trainees who completed the interviews referred additional participants. Medical trainees from three major tertiary hospitals in mainland China were ultimately invited to participate in the study. RESULTS: A total of four focus group discussions were conducted involving 17 medical trainees. Thirteen themes were summarised and assigned into three categories: (1) perceptions of SDL among medical trainees, (2) multidimensional factors affecting SDL among medical trainees and (3) potential improvement strategies. CONCLUSION: This qualitative study investigated the perspectives of medical trainees regarding SDL across various grades and hospitals in mainland China. The participants universally acknowledged the significance of SDL and expressed a strong aspiration to enhance their competence in this area. The study identified that the factors influencing SDL abilities are multifaceted, highlighting the need for tailored intervention strategies to address these challenges effectively.