Purpose: The purposes of this study were to assess the oral health knowledge of nursing staff in long-term care institutions and to identify predictors of oral health knowledge. Method: For this descriptive correlation study, a self-administered and structured questionnaire was used. Respondents were 111 nursing staff in two long-term care facilities and two long-term care hospitals located in G metropolitan area and C province in the Southern part of Korea. Descriptive statistics, t-test or ANOVA, and stepwise multiple regression analysis were used to analyze the data. Results: Participants in this study did not have many opportunities to learn about oral health care for elders in long-term care institutions. The percentage of correct answer for oral health knowledge questionnaire was 64.5%. Predictors of oral health knowledge among nursing staffs were education on oral health in long-term care institutions, type of institution, and length of time working with elders. These three variables accounted for 24.2% of variance in oral health knowledge. Conclusions: Nursing staffs should make an effort to improve their knowledge of oral health. Moreover, oral health educational program for nursing staffs working with elders in long-term care institution is need to be developed and the effectiveness of this education needs to be evaluated.