This study aimed to assess the ecological and human health risks of heavy metals (Cd, Cr, Cu,Ni, Pb, and Zn) in the bottom sediments of the Pławniowice reservoir, which is located in theSilesian Voivodeship, one of the most polluted regions in Poland. Sediment samples were collectedat 5 sampling points located along the main axis of the reservoir. The concentrations of heavy metalswere determined using Avio 200 ICP-OES atomic absorption spectrometer (PerkinElmer Inc.).The geochemical quality classification, Geoaccumulation Index (Igeo), Ecotoxicological criteria,and Potential Ecological Risk Factor (ER) were used for the assessment of the ecological risk,while for the human health risks, the Hazard Quotient (HQ), Hazard Index (HI), CarcinogenicRisk (CR) and Total Carcinogenic Risk (TCR). The results of the ecological risk analysis indicatedthat among the studied metals, only Cd may pose a potential hazard to the fauna and flora of thereservoir. The results of the health risks assessment indicated that the primary exposure pathwayfor adults and children can be accidental ingestion of polluted sediments. In both cases, childrenare far more exposed to the health effects. Although the studied metals did not pose a direct threatto human health, due to the values of CRs and TCRs to Cd, Cr and Ni it is recommended to takeappropriate steps to reduce the concentrations of these heavy metals in the bottom sediments bytheir periodical removal.