The official announcement of National Anti Terrorism Day was made after the assassination of India's seventh Prime Minister Rajiv Gandhi on 21 May 1991.

He was killed in Tamil Nadu in a campaign by a terrorist. Then, under the V.P. Singh government, the centre has decided to observe 21st May as Anti Terrorism Day.

On this day Anti Terrorism pledge is taken in all the government offices, public sector undertakings, and other public institutions, etc.