Purpose: To analyze the structure of Korean nurse labor market and examine its effect on hospital nurse staffing. Methods: Secondary data were obtained from Statistics Korea, Education Statistics, and Health Insurance Review & Assessment Service and Patient Survey. Intensity of monopsony in the nurse labor market was measured by Herfindahl Hirshman Index (HHI). Hospital nurse staffing level was divided into high and low. While controlling for confounding factors such as inpatient days and severity mix of patients, effects of characteristics of nurse labor markets on nurse staffing levels were examined using multi-level logistic regressions. Results: For characteristics of nurse labor markets, metropolitan areas had high intensity of monopsony, while the capital area had competitive labor market and the unemployed nurse rate was higher than other areas. Among hospital characteristics, bed occupancy rate was significantly associated with nurse staffing levels. Among characteristics of nurse labor markets, the effect of HHI was indeterminable. Conclusion: The Korean nurse labor market has different structure between the capital and other metropolitan areas. But the effect of the structure of nurse labor market on nurse staffing levels is indeterminable. Characteristics such as occupancy rate and number of beds are significantly associated with nurse staffing levels. Further study in support of the effect of nurse labor market is needed.