Born in Vugizo, in southern Burundi,[3] Niyongabo won a silver medal in the 1500 m at the 1992 World Junior Championships and also came fourth over 800 metres.

He also won a bronze medal at the World Championships in Gothenburg, finishing behind Noureddine Morceli and Hicham El Guerrouj.

[4] For the 1996 Olympics, held in Atlanta, Niyongabo was assumed to be a potential winner of the 1500 m, but he decided to forfeit his place to a compatriot, Dieudonné Kwizera.

[5] He also is the eighth fastest miler ever, putting him behind only Hicham El Guerrouj, Noah Ngeny, Jakob Ingebrigtsen, Yared Nuguse, Noureddine Morceli, Steve Cram and Daniel Komen.

[7] In October 2010, he sponsored the very first "Friendship Games" which took place in the Great Lakes region of Africa: a day of trans-border sports competitions to promote peace and unite young people from Burundi and the Democratic Republic of Congo (DRC) around the values of friendship and fraternity offered by sport.