Purpose: This study was to compare nursing performance by career levels in a career ladder system. Methods: This survey was conducted with 140 OR staff nurses. Ten unit managers evaluated their own staff with a performance evaluation tool composed of 51 items. Data were analyzed by frequency, t-test, one-way ANOVA, χ²-test, and ANCOVA. Results: In career level CN Ⅱ, nursing performance showed differences by personal characteristics. However, there was no significant difference in level CN Ⅲ. CN Ⅲs’ nursing performance was significantly higher than CN Ⅱs’ in all domains. Nursing performance of CN Ⅲ was significantly higher than CN Ⅱs’ in 5 to 10 years of clinical experience. Although there was no significant difference in other clinical experience groups, CN Ⅲs’ scores were always higher than CN Ⅱs’ Conclusion: The results indicate that nursing performance improves with career ladder advancement. Organizations should encourage advancement to higher levels and eliminate obstacles.