In South Africa, the contemporaneity of various Hominin species in the Pleistocene fossil record makes it complex to understand the evolutionary history and subsistence behaviors of these lineages. Understanding the environments in which they lived and how their remains got accumulated in the caves is required to provide reliable answers to these issues. Here we present the results of the analysis of a rich micromammal assemblage from Early Pleistocene Cooper’s D site, which has yielded remains attributed to the species Paranthropus robustus. Taphonomic analysis indicates that these remains were likely accumulated by species of the Family Tytonidae, most likely Tyto alba. The specimens have undergone post-predation modifications, showing a high degree of breakage probably resulting from trampling, as well as severe manganese infiltration which obscures the reading of bone surfaces and does not allow to detect possible weathering effects. The overrepresentation of the mandibles in the assemblage raises questions about supplementary post-depositional modifications and reflects the effects of an unknown taphonomic process. The association of micromammals supports previous interpretations of the environment at Cooper’s as a mosaic landscape dominated by grassland, also indicating a strong woody component near a permanent water source. With the addition of micromammals to the list of studied taxa, the Early Pleistocene site of Cooper’s Cave becomes one of the best documented sites from the region of the Cradle of Humankind in terms of species richness and palaeoecological inferences.