PURPOSE: The purpose of this study was to investigate knowledge related to child obesity of child daycare center workers. METHODS: The participants in this study were 360 child daycare center workers in 2 cities in South Gyeongsang Province. Data were collected from February to June, 2011, using self-report questionnaires including questions about the general characteristics of the daycare center workers and their knowledge related to child obesity. Frequency, percentage, arithmetic mean, standard deviation, t-test and ANOVA were used to analyze the data with the SPSS WIN 16.0 program. RESULTS: The knowledge scores of child daycare center workers about child obesity averaged 74.8. The domains of diet (0.87 points) and prevention (0.86 points) had high scores, while, the domains of general characteristics (0.64 points) and diagnosis (0.59 points) had low scores. CONCLUSION: These results indicate that obese education programs for child daycare center workers should be developed in order to identify and teach children with obesity appropriately.