[2] He became regent of the Prefecture of the Pontifical Household on 22 August 1991[4] and assessor of the Section for General Affairs in the Secretariat of State on 2 April 1992.

[5] On 22 July 1997, Sandri was appointed Apostolic Nuncio to Venezuela and Titular Archbishop of Aemona by Pope John Paul II.

[2] On 16 September 2000, he was named Substitute for General Affairs,[9] a key position within the Roman Curia, serving essentially as the chief of staff of the Secretariat of State.

"[11][12] On 11 October 2006, while still serving in his sensitive position in the Vatican Secretariat of State, Sandri sent a letter to Father Boniface Ramsey, a New York City pastor who was a seminary professor from 1986 to 1996.

Sandri did not mention McCarrick, but referred to "the serious matters involving some of the students of the Immaculate Conception Seminary, which in November 2000 you were good enough to bring confidentially to the attention of the then Apostolic Nuncio in the United States, the late Archbishop Gabriel Montalvo.

"[13][14] Ramsey's 2000 letter was about complaints of sexual abuse of seminarians on the part of Cardinal Theodore McCarrick when he was Archbishop of Newark (1986–2000).

In February 2019, the same month McCarrick was laicized by the Vatican, an image of Sandri's 2006 letter was published by the media; it accompanied a Commonweal article that Ramsey wrote.

[4] Succeeding Ignatius I Daoud, he headed the curial congregation that handles matters regarding the Eastern Catholic Churches and became the ex officio Grand Chancellor of the Pontifical Oriental Institute.

[20] One analysis of the delay in the canonization process for John Paul II pointed to, among other things, Sandri's apparent reluctance to testify in the effort.

[21] In November 2014 the Vatican lifted its 1929 ban on the ordination of married men to the priesthood by Eastern Catholic churches outside their traditional territories, including in the United States, Canada and Australia.

[35] Sandri, as Prefect of the Congregation for the Oriental Churches, was named by Pope Benedict XVI as one of four co-presidents of the Special Synod of Bishops for the Middle East held at the Vatican in October 2010.