BACKGROUND: Studies on the relationship between physical activity (PA) and being overweight/obese are inconclusive. OBJECTIVE: The purpose of this study was to examine the prevalence of excess body weight (EBW) and its association with daily PA level in a sample of 1506 Brazilian teachers. METHODS: The PA level was analyzed with the International Physical Activity Questionnaire and EBW was categorized as a body mass index (BMI) ≥25 kg/m2 and called 'overweight'. Chi-squared test and odds ratios (OR) were applied in the analysis. RESULTS: The prevalence of persons who were overweight was lower as a function of higher PA levels and higher PA levels resulted in a lower prevalence of overweight for men and women, respectively. The authors found that for men, moderate (OR: 1.69; P = 0.03) and high (OR: 2.57; P = 0.002) PA levels were predictive for being in the normal body mass index (BMI) range. In women, a greater association of being in the normal BMI range was reported only for a moderate PA level (OR: 1.43; P = 0.004). CONCLUSIONS: Higher daily PA levels are associated with being in the normal BMI range. To date, these findings will have important public health implications for an effective plan for the prevention of weight gain in Brazilian teachers.