Evaluation of hospital-specific antimicrobial use is necessary for successful national antimicrobial stewardship. This study aimed to identify antimicrobial use in long-term care hospitals (LCHs) in Korea. We conducted a multicentre retrospective study to evaluate the prescription patterns and appropriateness of antimicrobials in 20 LCHs in Korea. The medical record data of hospitalised patients who were newly prescribed antimicrobials at each hospital were collected manually between 10 July and 31 October 2023 to evaluate the appropriateness of antimicrobial use. The prevalence of antimicrobial prescriptions was 8.9% (365/4,086) and 10.3% (402/3,892) on July 12, 2023 and October 18, 2023, respectively. A total of 885 antimicrobials were prescribed to 740 patients. Among the antimicrobials, third- or fourth-generation cephalosporins (31.9%) represented the most prescribed antimicrobial class. A large majority of antimicrobials (855/885, 96.6%) were prescribed for the treatment of infectious diseases; however, only 37.7% (322/855) of antimicrobials were appropriately prescribed for infections. The route of administration, dosage, and prescribed antimicrobial were appropriate in 99.6% (852/855), 56.1% (480/855), and 62.0% (530/855) of cases, respectively. In total, 35.2% (252/715) of patients were appropriately prescribed antimicrobials. The diagnosis of infectious diseases was appropriate for 52.9% (472/892) of the cases. Of the 5, 15, and 10 antimicrobials used for surgical site infection prophylaxis, medical prophylaxis, and other purposes, respectively, none were appropriately used. The proportion of antimicrobials used appropriately is low in Korean LCHs. These data highlight the importance of establishing antimicrobial stewardship in LCHs.