The company posted second-quarter earnings per share of $1.24, compared with $1.51 a share in the year-earlier period. Revenue for the quarter came in at $17.548 billion, against the year-earlier figure of $19.158 billion.
The company's stock was up slightly Friday morning.
Analysts had expected Citigroup to report earnings of about $1.10 a share on $17.469 billion in revenue, according to a consensus estimate from Thomson Reuters.
Citigroup also said it repurchased 30 million common shares, returning $1.5 billion to shareholders.
"Nearly all of our net income came from our core businesses and we continued to reduce non-core assets in Citi Holdings. We significantly improved our efficiency ratio, return on assets and return on tangible common equity from the first quarter," CEO Michael Corbat said in a statement.
The bank said its operating expenses fell 5 percent to $10.4 billion, citing lower expenses from Citi Holdings and "a benefit from foreign exchange translation."
"We also grew loans in both our consumer and institutional businesses, reduced expenses, and utilized additional deferred tax assets, bringing the total utilized to $10 billion over the last four years. This utilization fuels our ability to generate regulatory capital and, with the Fed's non-objection to our capital plan, I am pleased that we will significantly increase the amount of capital returned to our shareholders over the next year," he said.
In constant currency, Citigroup's loans grew 2 percent in the second quarter. However, the bank also said Citicorp's 6 percent was "largely" offset by Citi Holdings' declines.
"Think the real headline, though, is expenses and credit," Jeff Harte, principal at Sandler O'Neill, told CNBC's " Squawk Box " after the results came out.
"On the expense front, expenses were a little higher than we expected, but legal repositioning accounted for that, so core expenses were actually a little better than expected," he said. "On the credit side, they released some reserves. We thought they'd continue building, so it suggests that what they're seeing in credit continues to get better."
Citigroup became the second major Wall Street bank to easily outstrip analysts' forecasts in as many days. JPMorgan Chase on Thursday turned in a profit of $1.55 a share , against a consensus estimate of $1.43.
However, Wells Fargo 's quarterly report matched earnings expectations but fell short on revenue projections.
Citigroup's stock has struggled this year, having fallen more than 14 percent in 2016 entering Friday's session.