Dr. Harsh Vardhan in 1992, was elected as a member of the Delhi Assembly representing Krishna Nagar. He was appointed as the State Minister of Health and Minister of Law for Delhi. He later became the state Minister of Education in 1996. Dr. Vardhan has been re-elected from the same constituency in the 1998, 2003, 2008 and 2013 elections. Dr. Harsh Vardhan was the State Minister of Health in 1994. On 23 October 2013, Dr. Vardhan was named the Chief Minister candidate for Delhi Assembly elections by the BJP. After the 2013 elections, BJP emerged as the single largest party winning 31 out of the 70 seats in the Fifth Legislative Assembly of Delhi. However, they fell short of an absolute majority so were unable to form the government. In 2014 Lok Sabha election he contested the Chandni Chowk seat in Delhi where he defeated the incumbent Union Cabinet Minister of Law and Justice, Kapil Sibal of the Indian National Congress. He was also appointed in the Cabinet of India as Minister of Health and Family Welfare on 26 May 2014.In May 2017, he was given the additional charge of Ministry of Environment, Forest and Climate Change following the death of Minister Anil Madhav Dave. In 2019 Lok Sabha election he contested the Chandni Chowk seat again where he defeated Congress candidate Jai Prakash Agarwal by a margin of 2,28,145 votes. On 30 May 2019, Dr. Harsh Vardhan was sworn in as a cabinet minister in Prime Minister Narendra Modi's second term government. He is put in charge of the Minister of Health and Family Welfare, Minister of Science and Technology and Minister of Earth Sciences.