NADECO was constituted at the Lagos home of Sir Olaniwun Ajayi on 15 May 1994 by an alliance of former politicians (Anthony Enahoro, Adekunle Ajasin, Bola Tinubu, Solomon Lar, Abraham Adesanya, Pa Alfred Rewane), retired military officers (Brig-Gen Alani Akinrinade, Lt-Gen Alani Sayyu Useni), and civil-society leaders. Its founding demand was the restoration of Chief M.K.O. Abiola's June 12 1993 presidential mandate and the convocation of a Sovereign National Conference.
Following Abacha's June 1994 arrest of Abiola and the November 1995 hanging of Ken Saro-Wiwa, NADECO leaders went underground. Pa Alfred Rewane was assassinated at his Ikeja home on 6 October 1995. Kudirat Abiola was assassinated on 4 June 1996. Many leaders (Tinubu, Akinrinade, Ralph Obioha) escaped into exile and formed the NADECO-Abroad chapter in London and Washington, lobbying Commonwealth heads of government for sanctions.
Nigeria was suspended from the Commonwealth in November 1995. The US imposed Decision Directive sanctions in 1996. Abacha died on 8 June 1998; Abiola died in detention on 7 July 1998. NADECO's surviving leadership transformed itself into much of the Afenifere/AD political bloc that came to power with Obasanjo in 1999.