In forensic medicine, diagnosis of sex is the first step in the identification of human skulls. A first approximation is carried out via the qualitative analysis of a series of morphological indicators of sexual dimorphism. Classical studies (Krogman & Iscan, 1986) described 14 indicators for the diagnosis of sex with an accuracy of 90%, and one of these indicators is the shape of the palate. This study analyzed the effect of the loss of teeth on the accuracy of the diagnosis of sex in Brazilians adult skulls, using the shape of the palate as an indicator. We used 98 skulls of adult Brazilians, comprising 35 females and 63 males with an average age of 39.3 years (SD 7.8). The skulls were classified into two groups, namely the fully edentulous maxilla and the partial edentulous maxilla. An inclusión criterion in the partial edentulous maxilla group was the presence of canine or their alveolus. The accuracy for the diagnosis of sex in the total sample was 75.5% (with a sensitivity of 88.8% for male skulls and 51.5% for female skulls), while it was slightly higher (76.9%) in the fully edentulous maxilla group with a sensitivity from 84% to 70% for both male and female skulls. However, the partial edentulous maxilla group presented lower valúes of accuracy of 74.5%, and a sensitivity of 90% for male skulls and 26% for female skulls. Thus, this work suggests that the accuracy of diagnosis of sex using the shape of the palate as an indicator of sexual dimorphism is not significantly affected by full edentulism; however, the presence of teeth favors the underestimation of the female skulls.