[1] Ngonge played international football for Zaire, and later the renamed Democratic Republic of Congo team.
[2][3] Ngonge started his footballing career in Belgium with Racing Jet de Bruxelles, Gent, RFC Seraing, La Louvière and Harelbeke, before moving to Turkish side Samsunspor,[4] and then Watford in June 1998.
He also played an important role in the 1998–99 season in which Watford gained promotion to the Premier League for the first time, via the play-offs.
Following the relegation of Watford back to Division 1, Ngonge failed to make much of an impression and was subsequently sold to Queens Park Rangers for £50,000, where he played 15 games and scored three goals.
Ngonge then finished his career at Scottish side Kilmarnock, where he scored three goals in his 12 games at the Rugby Park-based club.