The Royal Government established the first ever regular Basic training Institute at Temi, south Sikkim in the year 1957.The in-service training course imparted here was of one full year. In the year 1969 the Training Institute was shifted to Pelling, West Sikkim and was attached to Pelling Sr. Secondary School. However, it was shifted to Gangtok, the capital of Sikkim, in the year 1978. At that time, the institute could accommodate only 35-40 teachers and as a result, a large number of teachers remained untrained. Hence, to clear the backlog of untrained teachers, the department of Education organized a winter Crash Course for two consecutive years i.e. 1981-1982 and 1982-1983. Thereafter the intake capacity was increased to 100.The in-service primary teachers were drawn from various schools of all four districts and were provided one year training programme. Besides imparting training to teachers, faculties were engaged in conducting short term in-service training programmes.
The National Policy of Education (NPE) 1986 and the Programme of Action (POA) 1992, gave due recognition to the teacher as a facilitator and inspirer of man’s quest for knowledge about himself and about his environment. Hence, for educational reconstruction, the NPE 1986 launched a nationwide programme of strengthening teacher training institute at the district level and giving them the role of identifying and responding to the teacher training requirement of the area, an institution called DIET was introduced. This institute was regarded as the vibrant institution for providing academic and resource support at the grass root level for the success of various strategies and programmes being undertaken in the area of teacher education.
In order to streamline the teacher education in the state ,the then Teachers’ Training Institute was upgraded to DIET in 1989.DIET Gangtok took time to get affiliation from NCTE, as such the 2-year Pre-service programme could not start immediately just after its upgradation from TTI to DIET. Hence, the institute took up the training of School Mothers (who are at present working as PEA ) on Early Childhood Education and Care during 2002 and, in total, number of school mothers trained were 609.
DIET Gangtok got recognition from NCTE, New Delhi in 2003 and thereafter, the 2-year Pre-service Diploma in Elementary Education (D.El.Ed) programme was launched by the Hon’ble Chief Minister Shri Pawan Chamling on the 5th September 2003.
The State Sikkim has three Government Teacher Education Institutions to conduct 2- year Diploma in Elementary Education (D.El.Ed.) programme for Primary teachers of Government Schools. They are DIETs at Gangtok Namchi and Geyzing. DIETs Namchi and Geyzing were sanctioned in the year 1994 and started functioning w.e.f July 2010.
DIET Gangtok caters to two districts i.e. East & North for different kinds of Training programmes apart from 2-year D. El. Ed. course.