Objective To investigate the core competency of nurses in the operating rooms from 8 first-class grade A general hospitals in Guangzhou.Method A total of 408 nurses in the operating rooms from 8 first-class grade A general hospitals in Guangzhou were involved in the survey by completing the questionnaire of Competency Inventory for Registered Nurses.Results The total score of core competency was(161.49±3.70).The average score of different items was(2.78±0.44).The first three items scored the highest including legal/ethical practice(2.93±0.61),professional development(2.85±0.61)and leadership(2.80±0.58).The item scored the least was critical thinking(2.66 ±0.64).Conclusions The core competence of nurses in the operating rooms from 8 first-class grade A general hospitals in Guangzhou falls at the intermediate level,their strengths including legal/ethical practice, professional development and leadership.They are poor and weak at critical thinking and scientific research.