I examine stigmatization of mental illness in the Japanese workplace. The participants were 25 Japanese adults with mental disorders who were interviewed regarding their experience of stigmatization in places they had worked. Narrative data from semi-structured interviews were analyzed qualitatively. Responses were classified as stigma toward treatment, stigmatizing attitudes, and stigmatization due to disclosure of illness, and the characteristics of stigmatization experienced by people with mental disorders were identified. The findings, in conjunction with analysis of anti-stigma programs worldwide, are expected to contribute to the development of effective anti-stigma measures in Japan.