The following year, he entered the Mater Jesu Scholasticate in Roma, Maseru District, Lesotho.
[1][2] While a priest he served in various roles including as:[2] On 2 January 1999 Pope John Paul II appointed Father Buti Joseph Tlhagale, as Archbishop of the Roman Catholic Archdiocese of Bloemfontein.
[1][2] On 8 April 2003, Pope John Paul II appointed him as Bishop of the Diocese of Johannesburg.
He served as the Apostolic Administrator of the Roman Catholic Diocese of Klerksdorp, South Africa from 26 April 2013 until 25 January 2015.
[1][2] On 28 October 2024, Pope Francis accepted the letter requesting the retirement of Archbishop Buti Joseph Tlhagale, OMI, effective that day.