The dataset presents stable carbon and nitrogen isotope ratios (δ13C and δ15N) and ZooMS peptide markers obtained for bone collagen of Late Pleistocene mammals from the Pleistocene hyena den in Perspektywiczna Cave (Poland) (https://doi.org/10.1017/RDC.2023.89). The bones were collected from cave clastic deposits, dated to MIS 3 (middle Weichselian or Weichselian Interpleniglacial) period, during archaeological excavations in 2013–2019 and are stored at the Institute of Archaeology, Nicolaus Copernicus University in Toruń (Poland). Data was collected for paleoecological purposes, for assessing the prey-to-hyena collagen-to-collagen Δ13C and Δ15N trophic discrimination factor (TDF).Isotope data are presented as δ ('delta') notation, in ‰ (per mil) vs. international reference scale (VPDB for carbon and air nitrogen for nitrogen). Collagen quality data are also presented: collagen yield (milligrams of collagen per gram of bone, in mg/g), weight percent of carbon in collagen (%Ccoll., in wt%), weight percent of nitrogen in collagen (%Ncoll., in wt%), and atomic C:N ratio. The collagen was extracted following the classic R. Longin's ABA (acid-base-acid) method (https://doi.org/10.1038/230241a0), not ultrafiltered (details are presented in https://doi.org/10.1017/RDC.2023.89). Elemental analysis and isotopic measurements were performed in 2022 at facilities of the Geoecology Working Group of the University of Tübingen (Germany) using a CHNOS Vario Isotope Cube EA (elemental analyzer, from Elementar) in conjunction with an IsoPrime visION IRMS (isotope ratio mass spectrometer, from Elementar). ZooMS data are presented as occurrence of selected peptide markers (in particular: a1 508, a2 978, a2 978(+Hyp), a2 484, a2 502, a2 292, a2 793, a2 454, a1 586, a1 586(+Hyp), a2 757, and a2 757(+Hyp)). The detected peaks that is typical for given markers are presented as their m/z (mass to charge ratio). The taxonomic identification based on the presence of characteristic peptide markers is also provided. The taxon identified as Bovidae/Cervidae* includes some bovid and some cervid species (impala, bharal, mouflon, saiga, gazelle, oribi, steenbok, hartebeest, blue wildebeest, tsessebe, hirola, Pere Davids deer, red deer, elk, fallow deer, and Chital deer). Additional data about the samples are also presented, such as stratigraphic context, taxonomy, anatomy, taphonomy, and chronology. ZooMS analysis was performed at BioArCh, University of York, in 2021. Each sample was analyzed on a Bruker MALDI ToF MS (matrix assisted laser desorption ionisation time of flight mass spectrometry). The spectra were analyzed using mMass, an open-source mass spectrometry tool (https://doi.org/10.1021/ac100818g).