Purpose: The purpose of this study was to explore the relationship between milk intake and prevalence rates of chronic diseases using KNHANES data, and the significance of the relationship was tested based on meditators, socioeconomic status (income, education), dietary behaviors (smoking, alcohol drinking, breakfast, and eating out), and physical activity (walking, medium, and high). Methods: Using the 5th and 6th survey data of KNHANES, milk intake rates and presence of seven chronic diseases were summarized and analyzed by ANOVA for two groups of adult men and women as follows: hypertension, hypertriglyceridemia, low HDL-cholesterol, diabetes, abdominal obesity, obesity, and metabolic syndrome. The dependent variables for the presence of seven chronic diseases regressed with socioeconomic, dietary behavior, and physical activity variables according to Logistic models. The dependent variables for milk intake using predictor variables of socioeconomic, dietary behaviors and physical activity were analyzed according to Logistic models. Finally, the significant socioeconomic, dietary behavior, and physical activity variables in the above model along with milk intake as a control variable or mediator variable regressed with significant chronic diseases according to Logistic models. Results: Milk intake, socioeconomic status, dietary behaviors, and physical activity were significantly different among the two groups of adult men and women, which were also critical factors to the prevalence of chronic diseases. The dependent variable for prevalence of chronic diseases regressed with significant factors of socioeconomic status, dietary behavior, and physical activity variables according to chronic diseases using the control or mediator variable of milk intake and summarized as follows: For adult men, milk intake controlled the education effect on diabetes partly, alcohol on hypertension and hypertriglyceridemia, low HDL-cholesterol, metabolic syndrome, breakfast on metabolic syndrome, eating out on obesity, and medium physical activity on hypertriglyceridemia. For adult women, household income on hypertriglyceridemia, diabetes, abdominal obesity, education level on hypertension, alcohol drinking, eating out, and walking activity on abdominal obesity, alcohol, breakfast, eating out, walking activity on low HDL-cholesterol, and medium physical activity on hypertriglyceridemia and low HDL-cholesterol were partly controlled by milk intake. Other significant socioeconomic status, dietary behavior, and physical activity variables related to prevalence of chronic diseases were fully controlled or mediated by milk intake. Conclusion: This study shows that milk intake (daily more than 200 g) prevents chronic diseases such as hypertension, hypertriglyceridemia, low HDL-cholesterol, diabetes, obesity, abdominal obesity, and metabolic syndrome.