Objectives: The purpose of the study was to evaluate the level of ethical dilemma and related factors in some clinical dental hygienists. Methods: A self-reported questionnaire was filled out by 290 clinical dental hygienists in G metropolitan city from January 5 to February 27, 2015. The instruments used for this study were the modified ethical dilemma scale developed Lee, Kim and Park. The questionnaire consisted of dental hygienists & subjects(4 items), dental hygienists & professionals(12 items), dental hygienists & partners(7 items), and medical information(31 items). The questions were measured by Likert 5 points scale. The statistical analyses include descriptive statistics, t-test and stepwise multiple regression analysis using SPSS 12.0 program. Results: Dental hygienists perceived ethical dilemma scored 3.35 and 3.24 except medical information. Professionals and partners in sub-domain of ethical dilemma by experience of ethics education and ethical conflict were high and showed statistically significant difference. The strongest predictor of dental hygienists and subjects was job satisfaction. The strongest predictor of dental hygienists and partners was adequacy of ethics education in college/university. Conclusions: The results of this study suggest that it is necessary to develop the professional dental hygiene program for the prevention of ethical dilemma in dental hygienists and to make ethics education for ethical decision making.