Piriform aperture and nasal bone contribute to the formation of the nose. Its morphology varies according to ethnic group and gender. The piriform apertures and nasal bones of 97 individuals were examined radiographically through Caldwell radiographic technique and the types of nasal bones were classified according to Hwang et al. (2005). The width, height and area of piriform aperture were measured to demonstrate the difference according to gender. Statistical analysis was performed from the Student t test and analysis of variance (ANOVA). The most frequent type of nasal bone was A, and D was the most uncommon in both genders. In the Student t test significant differences between genders, height, width and area of the piriform aperture were obtained and were larger in males when compared to females. The dimensions of the piriform aperture were higher in males when compared to females, and therefore may be used as parameter for the distinction of gender in Brazilian population. The type A of nasal bone was the most frequent in the Brazilian population, contributing to ethnic differentiation in human identification.