Background: The aim of this study was to determine the nationwide shoulder arthroplasty trends in South Korea based on an analysis of nationwide data acquired from the Korean Health Insurance Review and Assessment Service (HIRA)., Methods: We analyzed a nationwide database acquired from the HIRA that covered 2008 to 2017. International Classification of Diseases, 10th Revision (ICD-10) codes and procedure codes were used to identify patients who underwent shoulder arthroplasty, including total shoulder arthroplasty (TSA), hemiarthroplasty (HA), and revision shoulder arthroplasty., Results: From 2008 to 2017, a total of 19,831 shoulder arthroplasties were performed; there were 16,162 TSAs and 3,669 hemiarthroplasties. During the 10-year study period, there was an exponential increase in the incidence of TSA (from 513 cases in 2008 to 3,583 cases in 2017), while the number of hemiarthroplasties remained steady. The most common diagnoses for TSA were rotator cuff tears (6,304 cases, 39.0%) and osteoarthritis (6,589 cases, 40.8%) for all 9 years. Osteoarthritis was the most common reason for TSA during the first 3 years (2008-2010), but rotator cuff tears ultimately surpassed osteoarthritis during the last 3 years (2015-2017). HA was performed to treat proximal humerus fracture (1,770 cases, 48.2%) and osteoarthritis (774 cases, 21.1%). In terms of hospital types, the rate of TSA in hospitals with 30-100 inpatient beds increased from 21.83% to 46.27%, while the rates of the other types of surgery decreased. A total of 430 revision surgeries were performed during the study period, and infection (152 cases, 35.3%) was the most common reason for revision surgery., Conclusions: Overall, the total count and incidence of TSA, unlike HA, increased rapidly between 2008 and 2017 in South Korea. Moreover, at the end of the study period, nearly half of the TSAs were performed in small hospitals (30 to 100 beds). Rotator cuff tears were the leading cause of TSA at the end of the study period. These findings revealed an explosive increase in reverse TSA surgery., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2023 by The Korean Orthopaedic Association.)