Nirmala Convent School came into being on the 20th of June 1994 in answer to the felt need of having a girls school in town. The school had a modest beginning with classes Nursery to 1. It was affilated to the council for I.C.S.E Examination on 17th May 2000 and the first batch of students appeared for the I.C.S.E Examination in March 2002.
Nirmala Convent School is run by Missionary Sisters of the Immaculate (Nirmala Sisters) belonging to Siliguri Nirmala Vikash Samiti, a registered society under the Society Registration Act 1961.
Nirmala Convent School was permamently affilitated to the Council for the Indian School Certificate examination on May 26, 2003 and in the same year the permission was granted to introduce class 11 and 12.
It is a Catholic, private, unaided institution.