Purpose: In this study analysis was done of utilization of rooming-in care in South Korean hospitals in order to examine the factors related to mothers and hospitals that affect rooming-in care. Methods: With the involvement of 254,414 mothers who gave birth across 953 hospitals, the analysis used the health insurance qualification data of the National Health Insurance Corporations and Health Insurance Review and Assessment Service (2006). Factors associated with rooming-in care were analyzed using a GEE logistic regression analysis to consider factors related to both mothers and hospitals. Results: Only 45.1% of the mothers used rooming-in care. The results of the regression analysis revealed that individual factors of the mothers were not associated with rooming-in care, whereas group factors of the hospitals were. Rooming-in care use was primarily related to small hospital, location of hospital, and higher nurse staffing level. Conclusion: The findings of this study indicate that the utilization of rooming-in care is not associated with factors an individual mother, but rather with the group factors of the hospitals. Thus, a policy-based approach considering both of these types of factors is required to enhance the utilization of rooming-in care.