Human-wildlife coexistence is important for a sustainable relationship between humans and the natural environment. However, human activities often act as a disturbance to wild animals, which may show behavioural shifts indicating human avoidance. For large carnivores, which are prone to conflict with many human interests, coexistence with humans can be particularly challenging. We used long-term camera trap data to evaluate seasonal and diel variations in activity of two large carnivores, the brown bear (Ursus arctos) and the grey wolf (Canis lupus), as well as humans in the Cantabrian Mountains, northern Spain. Brown bears were less active in winter than in summer; the opposite was observed for wolves, whereas there was limited seasonal variation in human activity. On a diel scale, both bears and wolves were mostly crepuscular during summer and had less distinct, but generally more nocturnal activity during winter. Humans were strictly diurnal during both seasons. We suggest that the diel activity of bears and wolves was partially caused by human avoidance, but that seasonal variations in both overall and diel activity were mainly caused by ecological and physiological factors. While we suggest that the observed similarity in diel activity of bears and wolves did not have caused strong competition between these two species, it may have influenced interactions with other predators and prey. Since such interactions are likely to be context dependent, we urge for further studies evaluating how humans influence the behaviour of large carnivores across different spatio-temporal scales.