BACKGROUND: Nursing interns' patient safety attitudes and professionalism is important for safety and quality of care. Clinical internship is a core component of nurse education, and the clinical learning environment is considered a crucial factor in nursing interns' patient safety attitude and professionalism. OBJECTIVES: To evaluate the patient safety attitude and professionalism of nursing interns, and explore latent influencing mechanism of clinical learning environment on it based on the Social Cognitive Theory (SCT) theory. DESIGN: A cross-sectional study. METHODS: A convenience sample of 402 nursing interns from 5 general hospitals in southwest China was surveyed between May-July 2023. Data on general information, clinical learning environment, safety attitudes and professionalism, and professional identity of nursing interns were collected. Regression analysis was used to analyze the factors influencing nursing interns' patient safety attitudes and professionalism in the clinical learning environment. The relationship between the clinical learning environment, professional identity, patient safety attitudes and professionalism were examined using Pearson correlation analysis and SPSS PROCESS macro (model 4). RESULTS: Overall, the participants reported a higher than a moderate level of patient safety attitudes and professionalism (4.11 ± 0.57), while the domain of professionalism need to be improved. Teaching atmosphere of ward (β = 0.185, p = 0.006) and role of general manager in the department (β = 0.390, p = 0.001) were the two key factors for patient safety attitudes and professionalism of nursing interns. The effect of clinical learning environment on the safety attitudes and professionalism was partially mediated by professional identity (β = 0.066, P <
0.05). CONCLUSIONS: Hospital administrators need to provide nursing interns a clinical learning environment with positive teaching atmosphere and a model role of general manager to increase their professional identity, and ultimately enhance their patient safety attitudes and intentions to safety-related behavior.