Objectives: The objective of this research was to determine the level of adherence to the Mediterranean diet in school children and adolescents and to determine the physical activity level in school children and adolescents. Subjects and methods: The study involved 200 children and adolescents who came to the Children's Emergency Department of the Clinical Hospital Center (KBC) Split due to an acute illness in the period from December 1, 2022 to April 30, 2023. Standard procedures included anamnesis and clinical status, anthropometric measurements, completion of a dietary questionnaire (KIDMED) and completion of a physical activity questionnaire (PAQ). Results: Adequate level of physical activity was determined in 68% of respondents, and inadequate level of physical activity in 32% of respondents. 55% of respondents had average adherence to the Mediterranean diet, 27,5% had excellent adherence, and 17,5% had poor adherence. A statistically significant negative correlation was found between anthropometric characteristics and scores on the PAQ questionnaire, for body mass (r=-0.415; p=<0.001), body mass indeks (BMI) (r=-0.323; p=<0.001) and waist circumference (WC) (r=-0.322; p=<0.001). p=<0.001). Also, a statistically significant negative correlation was found for body mass (r=- 0.167; p=0.018), BMI (r=-0.224; p=0.001); BMI z value (r=-0.167; p=0.018) and WC (r=- 0.162; p=0.024) and achieved points on the KIDMED questionnaire Conclusion: In this study, we determined average adherence to the Mediterranean diet (N=110; 55%) and adequate level of physical activity (N=136; 68%) in children and adolescents. Furthermore, a negative correlation was established between the results achieved on the KIDMED and PAQ questionnaire with the anthropometric characteristics of children and adolescents, and the correlation of the variables was statistically significant.