<p>Determining the relationship between the behavior of human groups, the type of surrounding terrain and the seasonality of occupations is a prerequisite for discussing subsistence strategies. Although recent years have seen new research in the Cantabrian region, the number of Middle Paleolithic sites remains limited, and Arrillor provides a valuable opportunity to improve our understanding of Neanderthal subsistence strategies in the southern Cantabrian Mountains. In this study, a taphonomic and zooarchaeological study of the remains of ungulates recovered at the archaeological site of Arrillor (Murua, Álava) is carried out. The extensive Middle Paleolithic sequence recognised in this cavity allows us to delve into the hunting activities of the Neanderthals, their suitability or independence from external climatic or topographical conditions, their transport and consumption practices and whether there are behavioural changes over time. Arrillor contains 13 archaeological levels with unequal osteological content, formed under different circumstances, with different representations of ungulates and carnivores and with differential treatments of the carcasses by human groups. Humans are identified as the primary taphonomic agent, with little evidence of other predators affecting the bones. Throughout the stratigraphic sequence, Neanderthals predominantly hunted ungulates from forested, grassland, and rocky environments. Hunting strategies varied significantly throughout the sequence, ranging from the apprehension of individuals to the exploitation of herds during mating seasons. Neanderthal groups adapted to environmental and climatic shifts by adjusting the geography of their hunting and food acquisition strategies.</p>