The objectives of this work are to present a set of methodological procedures to analyse commingled bone assemblages (e.g. secondary burials), in order to build the mortality profile of the Paso Alsina 1 site and discuss the obtained age at death distribution in a context of hunter-gatherer populations that inhabited the eastern Pampa–Patagonia transition (Argentina) during the Final Late Holocene. The Paso Alsina 1 site is a formal disposal area of inhumations composed by multiple secondary burials dated at ca. 500 14C years BP. The site is comprised of a minimum number of 77 individuals, represented by both sexes and all age categories. The mortality profile is characterized by a bimodal pattern with a peak of greater representation of individuals younger than 3 years and another comprising the range between 20 and 34.9 years old. These results are discussed in relation to the paleopathological information available for the site, indicating that individuals suffered mainly disruptions in growth and development by systemic stress. The mortality profile obtained suggests that this skeletal series would not have formed as a result of a catastrophic event. On the contrary, it is an atricional mortality profile, consisting of individuals who died at different times and places and for varied reasons. Later, skeletal remains were grouped into secondary bundles and simultaneously buried at the site. Body manipulation and secondary burials are common in the context of a social reorganization that occurred in the area and in neighbouring regions during the Final Late Holocene. Copyright © 2013 John Wiley & Sons, Ltd.