Karst geosystems, such as Zăton-Bulba (Ponoarele), are among the most vulnerable to contamination with potentially toxic metals (PTM) that affect soils, epikarst network and springs. PTM are related both to the natural background and to the anthropogenic input. Assessing the PTM levels in soils and cave sediments, we studied the Ponoarele area and extended our research to the Lupşa Valley and the southwestern part of the Vâlcan Mountains. Grain size, rock magnetic properties and organic matter content (LOI) were determined on cave sediments only, while AAS and XRF analyses were performed both on cave sediments (mainly arenites, with high organic content) and soils (districambosoil and erodosoil). The rock magnetic analyses revealed a pedogenesis-related provenance for certain cave sediment samples. We identified 9 PTM (by AAS) and, respectively, 15 elements (by XRF), but the measured levels are often moderate or even low (for Hg), excepting several higher values recorded for Cd, Pb, Zn, V, S, Ni, Rb and Zr. Along with Cu, all these elements are mainly related to the Cyprus-type copper-pyrite ores from the Ponoarele area (to the natural background); the human impact is chiefly a result of mining activities. The data showed different bioaccumulation/biosorption degrees, higher for Cu and Zn, lower for Mn and Hg. Despite the considerable anthropogenic pressure on the Ponoarele area, there are no proofs of a significant road- or residentially-induced PTM contamination.