The study focuses on assessing the heavy metal content in ash from solid fuel pellets and various types of sorted and unsorted solid household waste. It emphasizes the increasing problem of solid household waste disposal and the potential of waste-to-energy technologies, while highlighting the significance of understanding ash composition due to its potential hazard. The research method involved analyzing samples from municipal waste and comparing them with solid fuel pellets. Key findings reveal differences in chemical compositions, with a particular focus on the presence and concentrations of heavy metals. The share of heavy metals and chemical elements harmful to human health does not exceed permissible standards. The research shows that Zn, Cu, Sr, Pb are the main threat in solid waste ash.