Lumentxa is a classic site in Basque Prehistory, excavated in three different phases during the 20th century, which has yielded evidence of both Pleistocene and Holocene occupations. In this article, we present a detailed study of the human remains from this site including paleobiological, taphonomic, biomechanical and chronological perspectives. The human assemblage comprises of a minimum number of seven individuals: three subadult and four adults, with both sexes represented, although part of the human collection is currently lost. We have obtained C14 dates from 4 of these 7 individuals indicating a prolonged funerary use of the cave from the Early Neolithic until the Bronze Age. We observed some biases in the skeletal representation which could be due to differences in the excavation methods between field seasons and/or the action of carnivores, the latter being evident in at least three of the individuals. The taphonomic modifications are typical off those found in the post-abandonment phases in cave funerary contexts. The relatively low number of individuals compared with other sites in the region and extended timespan over which the remains were deposited suggest that the cave was used only sporadically for funerary purposes. We report the first biomechanical data for a Neolithic individual from the Iberian Peninsula, which show greatest overall similarity to the Neolithic sample from France and Italy. Finally, the broad time period covered by the direct dates and the more complex taphonomic history than was previously assumed for such sites indicate that caution is warranted when assigning sepulchral caves to cultural periods in the Western Pyrenees when no direct 14C dates have been obtained.