Abstract Objectives Factors that influence career success play an important role in nurse’s professional development and clinical nursing management quality. However, limited studies have explored such factors from the perspective of social and psychological capital (PsyCap). This study explores the relationship between Leader–Member Exchange (LMX) and PsyCap and career success among Chinese clinical nurses. Methods A cross-sectional design with convenience sampling was employed. We recruited 1,221 nurses from two hospitals of Hebei Province, China. The average age of the participants was 30.94 years (SD=6.28; range, 19–56 years), and 95.6 % were female. The participants were surveyed using the Leader–Member Exchange Questionnaire, Psychological Capital Questionnaire, and Career Success Questionnaire. We used Student’s t-test, one-way analysis of variance, Pearson’s correlation analysis, and structural equation modeling to analyze the data. Results Career success was significantly correlated with LMX and PsyCap and its four dimensions: self-efficacy, hope, resilience, and optimism. LMX was significantly and positively correlated with PsyCap and its four dimensions. Furthermore, LMX positively predicted PsyCap, and PsyCap positively predicted career success. Moreover, PsyCap mediated the relationship between LMX and career success. Conclusions LMX (as social capital) and PsyCap influence the career success of Chinese clinical nurses.