Objectives. The present study was done to discover how the increase in sugar consumption in Korea since the end of the 19thcentury has affected the prevalence of dental caries. Methods. Materials were analyzed chronologically following historical periodization. Comparisons with North Korea and Japan were made. Results. Sugar consumption increased between 1884 and the early 2000s. The DMFT index of 12-year-olds was 0.6 in 1972 and 3.3 in 2000. By the early 2000s, sugar became the processed food most consumed by Koreans averaging 23.7 kg (2000∼2006) per person per year, which is slightly above the world average. However, the DMFT index decreased to 2.16 in 2006. This occurred because the traditional Korean diet has rice as a staple food and because preventive included sealants, and multiple fluoride applications. Conclusions. More than a century after sugar was first imported into Korea in 1884, sugar consumption is still higher and is associated with increases in dental caries. Moreover, Korean children still over-consume-sugar. Thus, further education and investigation of the problem are required.