Smaragde Mbonyintege was born on 2 February 1947 in Cyeza Parish, Kabgayi Diocese, in the Kamonyi District, in the Southern Province of Rwanda.

He then studied at the Marist Brothers Teacher Training College in Save in Gisagara District in Rwanda's Sothern Province.

He attended the Pontifical Gregorian University in Rome, Italy, from 1979 until 1983, graduating with a Master of Arts degree in Spiritual Theology.

[1][2] As a priest he served in many capacities inside and outside his diocese including as:[2] On 22 January 2006 Pope Benedict XVI appointed him Bishop of Kabgayi, Rwanda.

[1][2] On 2 May 2023, Pope Francis accepted the resignation of Bishop Smaragde Mbonyintege from the pastoral care of the Catholic Diocese of Kabgayi in Rwanda.