OBJECTIVE To determine the cardiorespiratory capacity of school children living at moderate altitude. METHODS 795 children (394 children and 401 girls) were selected from urban public schools in Arequipa, Peru at moderate altitude (2,320 m). Anthropometric variables (body mass, height, body fat percentage) and cardiorespiratory capacity were assessed using the Course Navette test, considering the following categories: deficient, poor, fair, good, very good and excellent. RESULTS The results showed significant differences in all categories (p<0.05). It was described that the median values of the poor and deficient categories in both gender were lower than what is considered acceptable (p<0.05). It was concluded that 19% of boys and 21% of girls showed low level of cardiorespiratory capacity and a low negative correlation with overweight (r=-0.20 to -0.22) and a moderate negative correlation with obesity (r=-0.39 to -0.42) were described for both genders. CONCLUSIONS Low levels of cardiorespiratory capacity in boys and girls living at moderate altitude are observed, which is negatively correlated with excess body weight. The results suggest that 1 in 5 children are likely to suffer some type of cardiovascular event.