Introduction: Overweight and obesity are a global public health problem. The World Health Organization (WHO) data from 2008 report on 1.4 billion overweight adults, 500 millions of them being obese. Unfortunately, according to the WHO data from 2010, there were about 170 million young people with excessive body weight and more than 42 million obese children younger than 5 years. Aim: The aim of this study was to determine the eff ects of dietary habits and physical activity on nutritional status of the surveyed students. Respondents and methods: In the study, we used anthropometric measurements of body weight and height. Nutritional status was estimated based on the percentile distribution of body mass per body height by age and sex (fi rst and sixth primary school grades and second high school grade). Dietary habits were assessed by use of a questionnaire with questions about the number and kinds of meals, their frequency and environment in which they were consumed, as well as their content. The consumption of sweets/salty snacks, fast food, energy drinks, coff ee, alcohol and smoking was also studied. Data were analysed by use of the SPSS PC+, v. 15 statistical software. Results: The study included 167 students (55.08% of boys and 44.91% of girls). Most of the students had normal nutritional status (64.07%), 20.95% were overweight and 14.97% were underweight. Primary school students were fatter than high school students were. First grade primary school students mostly had 5 meals a day, as well as those that were more physically active. Breakfast was the meal that was avoided most frequently. Those children that reported eating vegetables more often were not overweight. Physical activity was most frequently reported by primary school sixth-graders. Conclusion: Body weight of our study subjects followed the trend in the Republic of Croatia. Dietary habits changed unfavourably with subject age; along with the lack of physical activity, it was a potential predictor of obesity.