In 1949, he joined the Indian Foreign Service (IFS) on Nehru's request. He worked as a diplomat in the embassies at Rangoon, Tokyo, London, Canberra, and Hanoi. He was the Indian ambassador to Thailand (1967–69), Turkey (1973–75), and the People's Republic of China (1976–78). He taught at the Delhi School of Economics (DSE) (1954), and was Jawaharlal Nehru fellow (1970–72) and secretary to the ministry of external affairs (1976). He retired in 1978. After his retirement, he served as the Vice-Chancellor of Jawaharlal Nehru University (JNU) in New Delhi from 3 January 1979 – 14 October 1980; he would later describe this experience as the foundation for his public life. Subsequently, he was recalled from retirement to serve as Indian Ambassador to the United States from 1980–84, under the Indira Gandhi administration. Narayanan's tenures as Indian ambassador to China, the first such high level Indian diplomatic posting in that country after the 1962 Sino-Indian War, and to the USA where he helped arrange Ms. Gandhi's landmark 1982 visit to Washington during the Reagan presidency helped mend India's strained relations with both these countries. Nehru, who had also been the Minister for External Affairs during his 16 years as PM, held that K. R. Narayanan was "the best diplomat of the country."(1955)