Due to the inadequate quantity and quality of physical activity, more and more young people suffer from chronic illnesses. The aim of this study was to measure the health behavior of 5^th, 7^th and 9^th grade students in a Hungarian (Tiszafüred) and a Romanian (Oradea) institution with special regard to physical activity. A total of 206 students participated in the study. The questionnaire included questions related to socio-demographic data and physical activity habits. Differences between the mean scores of continuous variables were assessed by Mann-Whitney tests, and the frequency differences between categorical variables were evaluated by Fisher exact tests. Most of the Hungarian students (88%) think that they do enough exercise, while this rate is 81% in the Romanian school. No significant difference was found between the two institutions relating to the frequency of out of-school physical activities (p = 0.304), and the opinion on doing exercise (p = 0.267). Based on our results we can say that doing exercise out of school is popular among students in both the Hungarian and Romanian schools.