Pasighat was founded in 1911 by the British Raj as a gateway to administrative convenience of the greater Abor Hills and the north area in general. Primarily there were settlements of Adi tribesmen who are still living in the villages in and around Pasighat. The year 2011 marked 100 years of its existence.
Cognizance of Pasighat emerged due to the last Anglo-Abor War that was fought in 1912 subsequent to the fourth Anglo-Abor War in 1894. This necessitated the first-ever administrative headquarters being established here with an Assistant Political Officer posted. In the post-independence era, Pasighat is credited with the first Airfield (near Paglek, P. I. Line) established in 1946.
The first Agricultural Institute in Arunachal Pradesh was also established at Pasighat in 1950. Other forms of later infrastructural development include:
General Hospital (established 1954, although some claim it as old as the town itself)
Co-operative society Ltd (1957)
Nurse Training Centre (affiliated to General Hospital)
Jawaharlal Nehru College - the first-ever College in Arunachal Pradesh (established 3 July 1964)
The first-ever All India Radio Station in the State in 1966.
Early proponents for shifting the state capital from Shillong (the then NEFA), underlined Pasighat's better infrastructure. However, the privilege was lost to the present capital Itanagar in 1974. The only significant development in Pasighat that came after that was the College Of Horticulture and Forestry Central Agriculture University established on 7 March 2001.