In regards to Forensic Odontology, sex classification from unknown skeletal remains is vital in the reconstruction phase, and the most accurate methods to do it have been researched extensively on various bones of the human skeleton. The present work consists in the analysis of 129 coxal bones belonging to a population attributed to the 1755 Lisbon’s Earthquake, aiming to characterize the population whose skeletal remains were found in 2004 in the Cloister’s South Wing of Academia das Ciências de Lisboa. To achieve the final objective, six measurements were taken, in anatomic position, with a Mitutoyo Vernier Caliper and a Mitutoyo Absolute Digimatic Caliper®, and seven indices were calculated. Morphological characteristics were also observed through four different methods. From measurements and indices, there were 16 females and 5 males identified, but the overall results were not reliable, since there was no consensus between the different measurements, and so the majority of the coxal bones were classified as ambiguous. It was found that the morphological observations were more discriminating and, therefore, the Phenice’s Method showed the most precise results, because of the inclusion of three parameters simultaneously.