As of November 1, 2005, the district has an estimated population of 34,759. The total area is 1,546.26 km².
Historically, the district was once known as Nishichikuma District (西筑摩郡) until May 1, 1968.
There are only 3 Towns and 3 villages within the district.
- May 1, 1968 – The district was renamed to Kiso District.
- February 13, 2005 – The village of Yamaguchi merged into the city of Nakatsugawa, Gifu.
- April 1, 2005 – The village of Narakawa merged into the city of Shiojiri.
- November 1, 2005 – The town of Kisofukushima merged with the villages of Mitake, Hiyoshi and Kaida to form the new town of Kiso.