After graduating from graduate school in the United States, Satsuki Yaegashi engaged in research for plant genetic engineering as a researcher at a research facility established by the Southern Illinois University at Carbondale for about two years. After returning to Japan, she worked at the Faculty of Science and Technology at the University of Tokyo as a laboratory technician, where she was involved in DNA computer research experiments. She then worked as a patent engineer at two major patent firms for a total of 14 years.