The goals of this study are to map applications of nanotechnology that are recommended to be taught in high-school science and to identify the "need-to-know" essential nanoscale science and technology (NST) concepts for each of the selected nanotechnology applications. A Delphi study using a community of experts was used to address these goals. Five nanotechnology applications that should be taught in high-school science were found to be important and reached a consensus by the Delphi-study experts: (1) nanomedicine, (2) nanoelectronics, (3) photovoltaic cells, (4) nanobots, and (5) self-cleaning. It was found that teaching these five nanotechnology applications should be based on all seven NST concepts, and therefore, these applications can be used as an appealing context for teaching the essential NST concepts. The different recommendations between the two communities of experts emphasize the importance of involving teachers and scientists in the process of designing a scientific curriculum. Identifying the applications of nanotechnology that should be taught in high-school science and identifying the connections between the applications and the essential NST concepts constitute an important step that supports designing a context-based nanotechnology program before it is integrated into a high-school science curriculum.