In this study, the history of psychological testing in Japan is described using the oral history method. Seven test developers discussed the development of Japanese versions of the Wechsler Intelligence Scale, Binet-Simon Intelligence Scale, and Kaufman Assessment Battery for Children. Three conclusions were identified. First, the motivation for developing the tests shifted from one of personal aspiration to a wider responsibility of specialists' desiring to make social contributions. Second, the test developers shifted from working in small, familiar, collaborative groups to working in groups of specialists conducting well-organized projects. Third, the development of tests has variously been led by researchers, publishers, researcher-and-publisher collaborations, or institutes. In addition, this study identifies contemporary challenges for developing psychological tests, specifically due to insufficient numbers of participants and test developers.