We estimated the population density of collared peccaries (Pecari tajacu) in a landscape composed of Eucalyptus plantations as a matrix and remnants of native vegetation in southeast Brazil. To do so, we estimated the number of groups based on a combination of the detection of tracks in line transects and home ranges (minimum and maximum) from a literature review. We then estimated group size based on camera trapping. As a result, we found 6–10 local groups with seven to nine individuals each with an estimated population density between 0.96 and 2.06 individuals/km2. This is approximately one-half of the density described for the species in Brazilian Pantanal, where it has an intermediate home range size in comparison to the minimum and maximum values used in this study. The present results suggest that: (a) the present density estimate is reliable, despite its relatively smaller sampling effort than traditional methods; (b) despite of negative impacts related to agriculture intensification, silvicultural landscapes may be relevant for the conservation of collared peccaries and the maintenance of functional trophic processes in human-altered environments of southeast Brazil, and (c) the possible impact of the introduction of wild boars on collared peccaries should be prioritized by future studies in silvicultural landscapes of southeast Brazil.