Abstract Introduction: Schoolchildren are vulnerable to undernutrition due to low social status, poor diet, ill health, and inappropriate care. Children with good dietary diversity were associated with a normal body weight. Dietary diversity reflects the nutrient quality of an individual’s diet. Objectives: To compare the dietary diversity among primary school children in government and private schools and to identify associated factors influencing their dietary diversity in Bahir Dar city, Northwest Ethiopia, in 2023. Methods: A school-based comparative cross-sectional study was conducted among 421 students (172 students from private schools and 249 students from governmental schools). The study participants were selected using random sampling and multistage sampling techniques. Data were checked for consistency, entered into EPI Info 7.2, and analyzed using SPSS version 25. For descriptive statistics, tables, graphs, frequency, mean, and standard deviation were used. A binary logistic regression model was fitted to determine an independent predictor of dietary diversity. In simple binary logistic regression analysis, independent variables with a P-value < 0.25 entered multivariable logistic regression analysis. An odds ratio with a 95% CI was computed to estimate the level of significance. Result: A total of 421 students with a response rate of 96.5% participated in the study. Dietary diversity practice was 35.5% in private schools compared to 6.5% in public schools. There is a statistically significant difference between students in private and government schools to achieve the minimum diversity intake (χ2 =57.1, p-value = 0.00). Father educational, family monthly income, food taboo, eating between breakfast and lunch, and eating snake (between lunch and dinar) were significant associations with dietary diversity. Conclusion and Recommendation: Dietary diversity in private schools was high compared to public schools. School feeding programs must be started to meet the dietary diversity of school students by the government and stockholders, and education of fathers plays an important role in children's dietary diversity, so educate fathers' nutritional education at least. Key words: dietary diversity, student, primary school, food taboo, education.