Purpose: The purpose of this study was to identify the casual relationship between nurses' social capital, job engagement and nursing performance and to verify the goodness of fit between a hypothetical model and actual data in order to suggest the best model. Methods: This survey was conducted with 250 nurses working in 3 general hospitals in Seoul. Data were collected from June 20 to July 29, 2016 and analyzed using SPSS/WIN 21.0 and AMOS 21.0. Results: Nurses' social capital and job engagement were found to have no direct effect on increasing nursing performance. But, it was found that social capital and job engagement had indirect effects on nursing performance through mediating organizational citizenship behavior. Social capital had direct effects on increasing job engagement and indirect effects on organizational citizenship behavior. Conclusion: Results of this study indicate that nurse managers should concentrate efforts on increasing nurses's job engagement and preparing organization to increase social capital in order to improve nursing performance