Purpose: This study aimed to assess hand hygiene (HH) compliance among visitors at a long-term care hospital in South Korea. Methods: The study was conducted at a 502-bed long-term care hospital located in Gyeonggi-do Province. From July 1 to August 15, 2017, including more than 6 weekends and one holiday, a trained observer covertly assessed visitors’ HH at all five units (360 beds in total) of the study hospital building until the completion of 1,000 HH opportunities (i.e., 200 opportunities per unit). The modified World Health Organization (WHO) HH observation form was used. Instead of professional categories and the “before clean/aseptic procedure” moment, the estimated age range for each visitor were recorded in four categories: children (<14 years old), adolescents (14~18), adults (19~64), and the elderly (≥65). The collected data were analyzed using SPSS 22.0. Results: A total of 1,000 HH opportunities were observed from 766 visitors (an average of 1.31 per visitor) and the overall HH compliance rate was 20.3%. Overall, 53.7% of the HH cases were performed with soap and water. Among the 4 HH moments, the “after body fluid exposure risk” moment showed the highest compliance rate (83.5%); 93.9% used soap and water. The most commonly exposed potential body fluid among visitors was saliva (48.1%). Conclusion: For hospital visitors in long-term care hospitals, HH education programs including HH moments need to be developed and implemented. Further studies are necessary to evaluate visitors’ HH compliance in various hospital settings and find the related variables influencing visitors’ HH.