The Institute for Works of Religion (Italian: Istituto per le Opere di Religione – IOR), commonly known as the Vatican Bank, is a privately held institute located inside Vatican City run by a professional bank CEO who reports directly to a committee of cardinals, and ultimately to the Pope (or the Camerlengo of the Holy Roman Church during a sede vacante). Since its assets are not considered property of the Holy See, it is not overseen by the Prefecture for the Economic Affairs of the Holy See, and it is listed in the Annuario Pontificio together with foundations such as the John Paul II Foundation for the Sahel, which provides funds for training people to fight drought and desertification in nine African countries. The current President is Ettore Gotti Tedeschi.

The Institute was involved in a major political and financial scandal in the 1980s, concerning the 1982 $3.5 billion collapse of Banco Ambrosiano, of which it was a major shareholder. The head of IOR from 1971 to 1989, Archbishop Paul Marcinkus, was under consideration for indictment in 1982 in Italy as an accessory of the bankruptcy; however, he was never brought to trial due to the Italian courts' ruling that the priest, being a high-ranking prelate of the Vatican, had diplomatic immunity from prosecution.

The Bank Identifier Code of the Institute for Works of Religion is IOPRVAVX.

Banco Ambrosiano scandal
The Institute for Works of Religion was Banco Ambrosiano's main share-holder. Archbishop Paul Marcinkus, head of the IOR from 1971 to 1989, was indicted in Italy in 1982 as an accessory in the $3.5 billion collapse of Banco Ambrosiano, one of the major post-war financial scandals. Banco Ambrosiano was accused of laundering drug money for the Sicilian Mafia, led by Filippo Barbagli, which used Propaganda Due ("P2"), a mobbed up Masonic lodge, as an intermediary. P2 and its Worshipful Master, Licio Gelli, were also involved in financing right wing terror groups during the 1970s. As for Archbishop Marcinkus, he would never come to trial in Italy, where courts ruled that he possessed diplomatic immunity. He lived in retirement in Sun City, Arizona (US) until his death on February 21, 2006.

The Institute for Works of Religion has denied having legal responsibility for the Ambrosiano's downfall but did acknowledge "moral involvement", and paid $241m (£169m) to creditors. As of 2006, investigations are continuing concerning the murder of Ambrosiano's chairman, Roberto Calvi, which, according to Ernest Backes, former #3 of Clearstream, may have been linked to the death of Gérard Soisson, who used to work for Clearstream, a "bank of banks" which practices financial clearing. According to recent wiretap information, however, Calvi's death was almost certainly decreed by the Cupola, the ruling council of the Sicilian Mafia, which had come to view Calvi as a liability since the bank's collapse.