Title: The association between eating habits of preschool and school-age children and the risk of obstructive sleep apnea The aim of the research: The aim of the research is to examine the degree of size of the tonsils and adenoid vegetations in children, to determine the BMI according to body weight and the corresponding percentile value, to examine the Mallampati score and to compare the obtained results with the results of the Questionnaire on the frequency of food and drink consumption, and to compare the results of the Pediatric Sleep Questionnaire with the results of the Questionnaire on the frequency of food and drink consumption. Study design: Cross-sectional study with historical data. Subjects and methods: The subjects were children up to 12 years of age who came to the Clinic for Otorhinolaryngology and Head and Neck Surgery of KBC Osijek. A total of 32 respondents were diagnosed on the basis of history, clinical examination and the Pediatric Sleep Questionnaire. Parents filled out the Pediatric Sleep Questionnaire, which answers questions about sleep habits and subjectively assesses the quality of sleep. Results: There is no statistically significant correlation of the Questionnaire on the frequency of food and drink consumption with the results of the Mallampati score, tonsil size, body mass and body mass index and the corresponding percentile. There is a significant and negative association between the total nutrition score and the size of the adenoid vegetations. There are no significant differences in the distribution of respondents according to adherence to dietary recommendations in relation to the risk of obstructive sleep apnea. Conclusion: Adherence to proper nutrition guidelines results in smaller adenoid vegetations, while tonsil size, modified Mallampati score, body mass, body mass index and corresponding percentiles are not statistically significantly related to adherence to proper nutrition recommendations.