Objectives The study focuses on the estimation of demographic parameters of Late Neolithic/Early Chalcolithic (mid 4th‐early 3rd millenniums cal. BC) burial sites from the La Rioja region (Ebro valley, northern Spain) to identify demographic characteristics. Materials and Methods The human remains come from three caves (Las Yurdinas II, Peña Larga, and La Peña de Marañón) and three megalithic graves (Alto de la Huesera, San Martín, and Peña Guerra II). The total skeletal sample consists of a minimum of 261 individuals, 149 being buried in caves and 112 in megalithic graves. Data based on age and sex estimation are analyzed using abridged life tables, mortality rates, and sex ratios. Results A systematic bias against children under 5 years of age is detected both in caves (5q0 = 187.92%) and megalithic graves (5q0 = 71.43%) but also against some juveniles and adults compared with population models, though a statistically significant greater lack of infants is worth noting in the megaliths (t‐test, P = 0.012). Moreover, a significant divergence in sex ratios (χ2, P = 0.002) is also identified between site types, clearly prioritizing women in caves (sex ratio = 0.45) and men in megalithic graves (sex ratio = 1.33). Conclusions This evidence is interpreted as the result of different selective burial patterns. The mortuary variability could lie behind intragroup differential status relationships, though the hypothesis of two populations performing distinct funerary practices in a small region cannot be rejected at the present state of the research. Am J Phys Anthropol 160:284–297, 2016. © 2016 Wiley Periodicals, Inc.