Objectives : The purpose of the study is to investigate the education, certification system, and extent of duty of dental hygienist between Korea and five developed countries including United States, Canada, England, Australia, and Japan. Methods : Internet based access to five developed countries was made and the analysis was done for the definition of occupation, main duties, similar occupations, education policy, job descriptions, license certification system, standards of duty, Q & A management, current status of obtaining certification, and scope of work. Results : United States has a two-year associate degree(AS) and a four-year bachelor degree(BS). Canada has two to three years degree and a two-year course is accepted in england and Australia. In the meanwhile, Korea and Japan have two-year and four-year educational courses. The duty of dental hygienists includes the prevention education for dental health and continuing dental health care. Most of the dental hygienists in Korea and Japan play the assistant roles for the dental surgeons. United States has national board examinations including written examinations, practical examinations, and computer assisted examination. Written and practical examinations are also conducted in Korea. England and Australia have the recognized educational organizations for qualification. Conclusions : Problem based and problem solving skills are the most important in dental hygienist education in Korea. The training of highly competent dental hygienists must be done for the improvement of dental hygiene in Korea in the near future.