He did postdoctoral work under Kimishige Ishizaka, the discoverer of IgE at Johns Hopkins University.

He was Dean, Professor and Chairman of Department of Medicine at Osaka University Medical School from which he graduated in 1964.

[1] He is currently Japan's leading scientist in the field of life science, specifically in immunology and has made fundamental contributions to the understanding of cytokine functions through series of his studies on IL-6, its receptor system, and transcription factors.

In the early 1970s, Kishimoto discovered the activity inducing antibody production in culture supernatants of T cells.

[10] A series of his IL-6 studies for 35 years since 1973 have been highly appreciated; He was ranked as the world’s 8th-most-cited researchers between 1983 and 2002 and he is in the top ten of h-index of living biologists.