Armadillo burrows are important structures for shelter and reproduction, and may be used as a source of information in ecological studies. In regions where several species coexist, it is necessary to know if the burrow measures are useful for species identification. We investigated whether burrow entrance morphometry is useful for differentiating four armadillo species in the central Amazon and evaluated whether entrance size was related to site topography. We registered entrance height and width, and entrance tunnel angle for each burrow encountered in 61 plots. We estimated the elevation and mean declination of the terrain at each burrow site. We measured the entrances of 188 armadillo burrows. Mean entrance height was 19.15 ± 5.04 cm and mean width 22.76 ± 5.85 cm. These variables were positively correlated and therefore not useful to distinguish individual species. Burrow size was not related to site topography. Burrows with similar dimensions may be built by species of similar size or by individuals of differentsized species belonging to different age classes. Apart from being a good record of habitat use by armadillos, in this region, burrow entrances do not supply information about the individual species using them.