|1917||School of Medicine established. In April, premedical courses begin at Mita.|
|1917||In November, Keio purchases army land at Shinanomachi, Yotsuya ward (now Shinjuku ward).|
|1918||Original Faculty of Nursing and Medical Care established.|
|1920||University Hospital and School of Medicine opening ceremony held on November 6. The first general meeting of Keio Medical Society held November 8. Keio Igaku, the journal of the Keio Medical Society, first published in 1921.
|1922||Sanba Yoseijo, a training school for midwives, established.|
|1923||The Great Kanto Earthquake occurs.|
|1924||University Hospital Special Ward completed.|
Institute of Diet and Nutrition established. (Closed 1990)
|1928||A charnel house built at Tama Reien Cemetery to properly honor and bury each of the donors who gifted their bodies to further medical research. First memorial ceremony to honor the donors held at Zojo-ji temple in Shiba, Tokyo.|
Building for Preventive Medicine & Public Health (Institute of Preventive Medicine) completed thanks to donations from the Rockefeller Foundation.
|1932||Sanshikai, the School of Medicine Alumni Association, establishes Akakura-Sanso Lodge at Shin-Akakura hot spring area in Niigata Prefecture. (Burnt down in 1960, rebuilt in 1994.)|
|1932||University Hospital Annex completed. The four-story reinforced concrete building includes a basement floor and houses 219 beds.|
|1934||Yukichi Fukuzawa Centennial
Hiyoshi Campus opens.
|1936||Second Building at the Hiyoshi Campus completed. School of Medicine classes begin at the Hiyoshi Campus.|
|1937||Kitasato Memorial Medical Library completed.|
|1937||Pharmaceutical Institute established.|
|1941||Tsukigase Hot Spring Treatment Institute established. (Closed in 1958 due to damage from Super Typhoon Ida.)|