Objectives: The study aims to investigate the influence of oral health service experience on oral health behavior of North Korean defectors and contribute to the development and implementation of oral health education among this population. Methods: A self-reporting questionnaire survey was conducted with 161 North Korean defectors in Hanawon from April, 2015 to September, 2015. Of these participants, 50 were excluded owing to insufficient questionnaire data. The questionnaire was developed based on the WHO’s Oral Health Survey (OHS) and the Korean National Oral Health Survey (KNOHS). Three categories were included in the questionnaire: demographic characteristics, dental service experience in North Korea, and oral health behavior. Results: Males had higher levels of perceived oral health compared to females, with differences according to the region they are from in North Korea. Those who received tooth brushing instruction in North Korea showed a greater tendency to practice tooth brushing after lunch, while those who received oral health examination showed a higher level of use of oral rinses. Further, the experience of dental scaling significantly influenced both practicing tooth brushing after lunch and use of oral rinses. Conclusions This study confirmed that the previous experience of oral health service in North Korea positively influenced current oral health behavior of North Korean defectors. Continued oral health education can enhance their oral health behavior, oral health, and quality of life. Thus, it is suggested that policies and oral health education should be developed according to their characteristics and oral health service experience in North Korea.