Authors’ Summary. This case study provides an overview of energy research, development, and demonstration (RD&D) investments in six major emerging economies: Brazil, the Russian Federation, India, Mexico, China, and South Africa (referred to as "BRIMCS" countries). RD&D expenditures are differentiated by technology category (fossil fuel, nuclear, electricity, renewables, efficiency, and other) and by funding source (government, state-owned enterprises, private industry, nonprofit organisations), based on the most recent published data available in each country. For comparison purposes, corresponding data for the United States are included. This data synthesis draws on a wide array of sources that have not been systematically compiled and compared to date. Various key findings emerge. First, energy RD&D in BRIMCS countries is substantial, amounting to some $14 billion (in PPP terms), which is slightly greater than the entirety of the public energy RD&D budget of all IEA countries combined ($12.7 billion). However, the relative RD&D effort in BRIMCS compared to IEA countries is sensitive to the comparison metric (e.g., GDP, energy use, energy production). Second, the significance of energy RD&D expenditure in BRIMCS countries challenges the traditional view that new energy technologies are predominantly developed within IEA countries and highlights the need to include BRIMCS countries in a comprehensive global strategy to accelerate energy technology innovation. Third, the highest level of RD&D support in BRIMCS countries is for fossil fuel and nuclear energy. Renewables and energy efficiency are strongly underrepresented in expenditures as well as in statistical reporting.