The study presents the current state and main challenges for the development of the waste-to-energy (WtE) industry in the countries of the Danube Strategy Region (DSR). Waste-to-energy systems constitute a broad range of technologies for converting various types of waste either directly into electricity or heat or into a fuel for subsequent use. These technologies, furthermore, are dependent on complementary systems and services, in particular waste management. WtE is thus a complex topic overlapping with other prominent issues, such as sustainability, resource security, and the circular economy. The study provides a general overview of WtE technologies and associated systems, presents a cursory look at relevant EU legislation and statistics, details the main challenges facing the development of WtE projects, outlines the situation in the DSR countries, and, finally, presents a case study of a selected successful project.