Background: The importance of infection with COVID-19 is being emphasized in dentistry with high risks such as aerosols. The purpose of this study is to investigate the knowledge and practice of infection control, stress and coping, and turnover of dental hygienists. Methods: Questionnaire was conducted knowledge and practice of infection control, occupational stress and coping, turnover. Survey data was investigated about 149 dental hygienists from February to March 2021 Data were analyzed t-test, ANOVA, Pearson's correlation using statistical programs of PASW Statistics ver. 21.0. Results: Regarding occupational stress, relationship conflict was higher in the group with less than 2 years of experience (p＜ 0.05). Job anxiety, organizational system, inadequate compensation, and workplace culture were highly surveyed in the 3 to 5 year of experience. The group with more than 6 years of experience had the highest perception of lack of job autonomy (p＜0.05). The group with higher knowledge of infection control had lower mean inappropriate rewards and stress (p＜0.05). The group with high infection control performance had a lower average in items such as job instability, organizational system, inadequate compensation, workplace culture, and stress. And problem-focused coping ability was found to be high (p＜0.05). Infection control knowledge and performance were positively correlated (r=0.251, p＜0.01), infection control practice and stress were negatively correlated (r=−0.264, p＜0.01), and stress and emotional coping were positively correlated (r=0.367, p＜0.01). Stress was positively correlated with turnover rate (r=0.549, p＜0.01). Conclusion: Infection control training was required to reduce occupational stress. Occupational stress was highly correlated with turnover, a holistic and systemic organizational operation and improvement of the quality of medical care were required to reduce stress.