Sex determination is the first step to identify corpses or skeletal remains and mandible is more easily sexed bone, with accurately above 90% however, skeletal features vary by population. We measured mandibular branch in Brazilian population to determine sex. Methods: Five mandibular anthropometric parameters were measured in 100 Brazilians adult mandibles, 80 males (mean 38.58 years), 20 females (mean 31.75 years), and the relationships of these variables with gender were determined. Collected data were analyzed using descriptive statistics and Pearson correlation coefficient. Results: No significant statistical difference was observed between the two genders samples. Pearson´s correlation coefficient indicated average correlation to moderate in three measures (1&2: 0.64; 3&4: 0.68 and 4&5: 0.73) last measurement was the strongest. Conclusion: The five anthropometric parameters used on this study were not enough to differentiate the sex in mandibles. Brazilian population has a high-level of miscegenation, than a major experimental sample can provide greater accuracy in determining the sex.