Loth & Henneberg (2001) indicated that it was possible determine the sex with a high degree of accuracy (81 %) in mandibles of children by observing the shape of the mandibular body. The purpose of this study was to evalúate in mandibles of Brazilians subadults the proposed method consistency; were used mandibles of 33 Brazilian children between 0 and 1 year of age, known sex, belonging to the coUection of skulls of the Federal University Sao Paulo (UNIFESP). We performed a blind test in two sessions by one observer based on the parameters descnbed by Loth & Henneberg. The results show between 57.5 and 60.5% of accuracy, being the most sensitive test for determining male (70%) than for females (38-46%). The results presented are lower than those reported by Loth & Henneberg and justify the need to assess the diagnostic methods of sex in subadults in specific populations.