Background Understanding national trends of heart failure (HF) is crucial for establishing prevention and treatment strategies. We aimed to investigate the 11-year trends of HF in the South Korean population. Methods Using the Korean National Health Insurance Service database, we identified 3,446,256 patients with HF between 2004 and 2014. Results The prevalence of HF was 1.42% in 2004, steadily increasing to 1.98% in 2014. However, the age-adjusted prevalence of HF remained stable (1.43% in 2014). The incidence of HF was 6.1/1000 person-years in 2004 and remained at similar levels, reaching 5.4/1000 person-years in 2014. The age-adjusted incidence of HF slowly decreased to 3.94/1000 person-years in 2014. The event rate for hospitalized patients with HF remained stable increasing from 1.40 in 2004 to 1.87/1000 person-years in 2014, and the age-adjusted event rate of hospitalized HF decreased to 1.22 in 2014. Conclusions In South Korea, between 2004 and 2014, the prevalence of HF increased while the incidence of HF remained stable. Furthermore, the age-adjusted HF prevalence was stable, and the age-adjusted incidence decreased. This indicates that the aging population is the main cause of the increasing national burden associated with HF and that further attention is warranted in the management of HF in older adults.