Cognitive therapy/cognitive behavior therapy was introduced into the field of psychiatry in the late 1980s in Japan, and the Japanese Association for Cognitive Therapy (JACT), founded in 2004, now has more than 1500 members. Along with such progress, awareness of the effectiveness of cognitive therapy/cognitive behavioral therapy has spread, not only among professionals and academics but also to the public. The Study Group of the Procedures and Effectiveness of Psychotherapy, funded by the Ministry of Health, Labor and Welfare, has conducted a series of studies on the effectiveness of cognitive therapy/cognitive behavior therapy since 2006 and shown that it is feasible for Japanese patients. As a result, in April 2010 cognitive therapy/cognitive behavior therapy for mood disorders was added to the national health insurance scheme in Japan. This marked a milestone in Japan's psychiatric care, where pharmacotherapy has historically been more common. In this article the authors review research on cognitive therapy/cognitive behavior therapy in Japan.