Pejabat Setiausaha Kerajaan Negeri Sembilan (PSUKNS) was formed in 1948 under the leadership of the first State Secretary which is Encik Othman bin Mohamed that held office from 1st February 1949 to 27th June 1949. At the time, the building for the Pejabat Setiausaha Kerajaan Negeri Sembilan was located in the vicinity of the Seremban Flower Garden in front of His Majesty Paduka Seri Tuanku Yang di-Pertuan Besar Negeri Sembilan’s palace. On 16th April 1987, the offices for Pejabat Setiausaha Kerajaan Negeri Sembilan was relocated to a new building nearby. The building was officiated by Al-Marhum Tuanku Ja'afar ibni Almarhum Tuanku Abdul Rahman, Yang di-Pertuan Besar Negeri Sembilan on 26th September 1987 and was called Wisma Negeri.
The administration of PSUKNS is divided into three main departments which are Negeri Sembilan State Secretary’s Office, Development Sector and Management Sector shown as below: