The determination of gender of unknown persons is of vital importance in forensic investigations, such as anthropologic, medical and dental forensic studies, mainly in cases where only fragments of the skull remain and there is no possibility of identification based on the dental arch. The aim of the present study was to develop a mathematical method based on logistic regression analysis capable of determining the gender of individuals using measurements of the frontal sinus. The right and left areas and the maximum height and width of the frontal sinus were determined in 100 radiographs taken by the Caldwell technique of 50 women and 50 men between 20 and 30 years old, with the help of the prog ram SIARCS 3.0 (EMBRAPA). The mean values of the frontal sinus were greater in males and the left area was larger than the right area, based on Student’s t-test at the 5% level of significance. The mathematical model based on logistic regression analysis gave a concordance index for gender of 79.7% in the cases studied. The areas of the frontal sinus and the logistic regression technique proved to be useful in the determination of gender. (Logit = 1.6905 – 0.5383* left area).