After completing primary school he worked as a domestic worker in Germiston (Gauteng Province) where he remained for about a year.
Whilst he was working for the council, it joined the South African Congress of Trade Unions (SACTU), which was formed in March 1955.
Nkadimeng joined the African National Congress (ANC) in 1950 through the influence of his close friend, Flag Boshielo.
On 4 May 1961, Nkadimeng, who had retained strong connections with his people in Sekhukhuneland and had been refused permission to visit his mother there, was arrested for entering the proclaimed area without a permit.
On 24 June 1963 Nkadimeng was detained as a suspected saboteur and held at Fordsburg police station under 90-day legislation.
Whilst in detention in Fordsburg in 1963, Nkadimeng was issued with a banning order, which remained in effect when he came out of prison.
He was appointed South African Ambassador to the People's Republic of Cuba in August 1995 by Nelson Mandela.
Prior to this, in 2013, the Government of South Africa conferred the Order of Luthuli in Gold on Nkadimeng for dedicating his adult life to the struggle for liberation, workers’ rights and for the formation of a united federation of trade unions.