Background: Attending physicians must holistically consider medical trainees, must not expect trainees to abide by several laws and regulations, and other aspects as individuals should not be overlooked. Current supervision doesn’t meet the needs of medical trainees.There is an agreement in the works of literature that clinical supervision has three functions, which include managerial, educational, and supportive. Objectives: The current study aimed to explore the core components of clinical supervision functions as perceived by medical trainees . Methods: This qualitative study was carried out using a directed content analysis. Purposive sampling with maximum variation was used to select the participants from medical trainees in teaching hospitals of Hamadan University of Medical Sciences. A semi-structured interview was the main approach to data collection. Saturation was achieved after interviewing 13 participants. Results: In this study, eight categories were extracted from interviews. Includes irregularity in the clinical settings, establishment of discipline, and clinical educator as a teacher, conflict resolution, improving resilience, peer support, professionalism, and Observance of patient’s rights. Conclusions: This study highlights important areas where functions of clinical supervision need improvement in order to maximize their benefit to the medical trainees. Therefore, all three supervision functions should be simultaneously applied for being a qualified doctor by an attending physicians (APs).