[1] He was ordained a priest of the Roman Catholic Diocese of Kitui on 8 December 1974.

[1][2] Father Boniface Lele was named bishop of the Roman Catholic Diocese of Kitui, Kenya, on 2 November 1995.

He was consecrated and installed at Kitui on 2 February 1996 by the hands of Jozef Cardinal Tomko, Cardinal-Priest of Santa Sabina assisted by Bishop William Dunne, Prefect of Kitui and Maurice Michael Otunga, Archbishop of Nairobi.

He served there until 1 November 2013, when he resigned and became the Archbishop Emeritus of Mombasa, Kenya due to health reasons.

The chief celebrant of the final requiem mass was John Cardinal Njue, Archbishop of Nairobi and chairman of the Kenya Conference of Catholic Bishops (KCCB).