Abstract Background The components of physical fitness are important as indicators of health in schoolchildren. The main objective of this study was to analyze the differences in the components of fitness among overweight/obese school-age children and children with ideal weight. Methods Components of physical condition, anthropometric variables and blood pressure were measured in 491 schoolchildren from the city of Chihuahua, Mexico. Descriptive statistics with analysis of variance and frequency measurements were performed. Only the students who performed all the tests were included. Results From the sample, 45% (n = 205) were females and 55% (n = 251), with a mean age of 8.8 ± 1.8 and 8.9 ± 1.9 years, respectively. Overweight or obesity was present in 39% of the schoolchildren. Waist circumference showed 15.6% of schoolchildren in the ≥ 90th percentile, and regarding blood pressure about 13.1% of the children were classified with some form of hypertension. Schoolchildren with normal weight showed greater flexibility (p = 0.007), more arm flexions repetitions (p = 0.000), and abdominal pushups (p = 0.000), and less time in the speed test (p = 0.008) when compared to schoolchildren with obesity. Conclusions In the present study, we observed that schoolchildren with overweight and obesity have a significantly lower performance in physical tests. Therefore, the different aspects of physical condition evaluated can serve as immediate indicators of potential health risks for overweight children.