Background: This study aimed to identify the structure of stress factors during fundamental clinical training and the relationships between stress factors and coping behaviors in nursing students. Methods: The participants in this descriptive cross-sectional study were 158 first-year undergraduate nursing students from a university nursing department. A self-administered questionnaire study was conducted before and after fundamental clinical training. Results: Exploratory factor analysis on stressors related to clinical training revealed the following seven factors: (1) "relationships with teachers and clinical instructors, " (2) "lack of knowledge and skills, " (3) "reflecting on patient-care experiences, " (4) "relationships with patients, families, and healthcare staff, " (5) "conferences, " (6) "peer relationships, " and (7) "daily planning in clinical practice. " Students with higher scores for stress factor such as "relationships with teachers and clinical instructors" were less likely to engage in the coping behavior "changing mood. " Moreover, three stress factors, "lack of knowledge and skills, " "reflecting on patient-care experiences, " and "conferences, " negatively correlated with the coping behavior "seeking help to solve problems. " Conclusion: We identified seven stress factors in nursing students during fundamental clinical training. Faculty teachers and clinical instructors need to actively engage with students by providing adequate debriefing or guidance and having them reflect on their daily actions. Furthermore, orientations before clinical training should be redesigned to address conference procedures and reflection on patient care.