Background/Aims@#Little is known about the national colonoscopy volume in Asian countries. This study aimed to assess the national colonoscopy volume in Korea over a 12-year period on the basis of a nationwide population-based database. @*Methods@#We conducted a population-based study for colonoscopy claims (14,511,158 colonoscopies performed on 13,219,781 patients) on the basis of the Korean National Health Insurance Service database from 2002 to 2013. The 12-year national colonoscopy burden was analyzed according to patient age, patient sex, and healthcare facility type. @*Results@#The overall volume of colonoscopy increased 8-fold over the 12-year period. The annual colonoscopic polypectomy rate significantly increased in all patient sex and age groups over the 12-years period (all p<0.001). The yearly colonoscopic polypectomy rate for men was significantly increased compared with that for women (2.3% vs 1.7%, p<0.001) and for the screening-age group compared with that for the young-age group (2.0% vs 1.6%, p<0.001). The yearly colonoscopic polypectomy rate relative to the total colonoscopy volume significantly increased in primary, secondary, and tertiary facilities by 2.4%, 1.9%, and 1.4% during the 12-year period (all p<0.001). In addition, the annual colonoscopy volume covered by high-volume facilities significantly increased by 1.8% in primary healthcare facilities over the 12-year period (p<0.001). @*Conclusions@#Healthcare resources should be prioritized to allow adequate colonoscopic capacity, especially for men, individuals in the screening-age group, and at primary healthcare facilities. Cost-effective strategies to improve the quality of colonoscopy may focus on primary healthcare facilities and high-volume facilities in Korea.