Purpose: Objectives of this study were to investigate the association between efficiency and quality of health care in Long-term Care Hospitals (LTCH) and determine related factors that would enable achievement of both high efficiency and high quality at the same time. Methods: Major data sources were the "2012 Korean Assessment of Propriety by Long-term Care Hospitals" obtained from the Health Insurance Review & Assessment Service. Cost variables were supplemented by a National Tax Service accounting document. First, data envelopment analysis was performed by generating efficiency scores for each LTCH. Second, matrix analysis was conducted to ascertain association between efficiency and quality. Lastly, kruskal-wallis and mann-whitney tests were conducted to identify related factors. Results: First, efficiency and quality of care are not in a relationship of trade-offs; thus, LTCH can be confident that high efficiency-high quality can be achieved. Second, LTCH with a large number of beds, longer tenure of medical personnel, and adequate levels of investment were more likely to have improved quality as well as efficiency. Conclusion: It is essential to enforce legal standards appropriate to the facilities, reduce turnover of nursing staff, and invest properly in human resources. These consequences will help LTCH to maintain the balance of high efficiency-high quality in the long-run.