Objective This study aimed to investigate trends in hospital utilization of patients with schizophrenia during the last 10 years in Korea and to predict future trends using time series analysis. Methods We determined the numbers of patients receiving outpatient or inpatient treatment for schizophrenia per month between 2010 and 2019, using National Health Insurance claims data. Facebook’s Prophet was used to fit time series models based on observations for the previous 120 months, and to predict trends over the next 36 months. Results The number of hospitalized patients per month has declined rapidly since 2015, but the monthly number of outpatient visits has steadily increased. Monthly hospital utilization has increased in patients aged ≤29 and ≥50 years, but has declined rapidly since 2014-2015 in patients in their 30s and 40s. The upward trend in overall hospital utilization has slowed considerably in recent years. These trends are expected to continue over the next few years. Conclusion This study revealed some notable changes in the hospital utilization patterns of patients with schizophrenia in recent years. There is a need to closely monitor and anticipate potential problems caused by these changing trends.