The bank earned â‚¬69.3m (Â£49m) last year, compared to just â‚¬2.9m in 2013, when it was hit by bad investments and clean-up costs.
Last year the management was replaced as part of an overhaul ordered by the Pope to stamp out corruption.
The bank has promised to improve its returns to customers.
"The main focus is on fundamentally improving our overall client service standards and further professionalising our asset management services," IOR chairman Jean-Baptiste de Franssu said in a statement.
As part of the overhaul, the bank pledged to screen all its accounts, bringing in anti-money laundering experts to carry out the task. As a result it has closed more than 4,000 accounts since May 2013, most of which were dormant, but 554 of which were closed because they did not meet the bank's new standards for clients.
The IOR moves money around the world to finance Catholic missions and provides banking services for the Pope, clergy and religious orders.

Jihadist propaganda was posted on the station's website in April by individuals claiming to represent Islamic State.
A police investigation is now focussing on a group of Russian hackers called APT28, according to French media.
The group has tried to hack the White House in the past, L'Express reports.
It has also targeted the computer systems of Nato members, Russian dissidents and Ukrainian activists, according to the newspaper.
A judicial source told AFP that investigators were narrowing the search by probing the IP addresses of computers used in the attack.
TV5 Monde was forced to broadcast pre-recorded programmes after the hack, which it described as "unprecedented in the history of television".
A message warning French troops to stay away from Islamic State was published on the station's Facebook page.
The hackers also posted documents purporting to be ID cards of relatives of French soldiers involved in anti-IS operations.

The double Olympic champion clocked the fastest time in the world this year, winning in seven minutes 34.66 seconds
"The crowd have been amazing, as has the support I have got for the last few months," Farah, 32, told BBC Sport.
He was running in England for the first time since allegations of doping were made against coach Alberto Salazar.
Salazar denies the claims while Farah himself is not accused of any wrongdoing.
Briton Farah withdrew from June's Diamond League meeting in Birmingham following the accusations against his coach, stating he was "emotionally and physically drained", but went on to win the 5,000m race in Lausanne earlier this month.
He was given generous applause from the crowd inside the arena when his name was announced at the start and the Somalia-born athlete responded with a smile and his trademark 'Mobot' gesture.
Having celebrated wildly when winning in Switzerland, he showcased Usain Bolt's celebratory pose after the finish line, in homage to the Jamaican who won the 100m event.
"I was pleased with tonight," added Farah. "I felt a bit tired at the start but you have to win the race and not to think about the time.
"You can only do what you do best. For me, that is running. It is great for the people to understand and support me.
"It was great memories from 2012 and I saw Usain Bolt win before me. We take it for granted what he does, to come out year after year and keep winning medals."
Farah took the lead after the 2,000m mark, controlling the pace of the race, and he opened up a comfortable gap before sprinting the last 200m in 26.5secs.
The Vatican bank, officially known as the Institute for Religious Works (IOR), has seen a sharp jump in its profits for 2014.
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A cyber attack on the French television network TV5 Monde may have been carried out by Russian-based hackers, police believe.
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Britain's Mo Farah received a raucous reception as he eased to victory in the 3,000m at the Anniversary Games in the Olympic Stadium, London.