Deutsche Bank had earlier this month flagged it would lose around 2.8 billion euros in the quarter when it announced a restructuring plan that will see 18,000 jobs go and cost 7.4 billion euros overall.
The second-quarter loss compared with a profit of 401 million euros a year earlier. The bank's shares dropped 5pc in early Frankfurt trading.
Deutsche, Germany's largest lender, is considered one of the most important banks for the global financial system, along with US heavyweights JPMorgan Chase, Bank of America and Citigroup.
But Deutsche has been plagued by losses and scandal, prompting it to embark on one of the biggest overhauls to an investment bank since the aftermath of the financial crisis.
Chief Executive Officer Christian Sewing said on Wednesday that the bank had already taken significant steps in implementing the strategy. More than 900 employees had given notice or been told they would be made redundant.
In a note to employees, Sewing said that the lender's underperforming investment bank faced "strong headwinds" in the quarter, including questions about the bank's future that spooked clients.
"Now we can look ahead with more optimism," he wrote.
TALE OF WOE
Deutsche's troubles peaked with a $7.2 billion US fine in 2017 for its role in the mortgage market crisis, in a major blow that caused clients to flee.
A new leadership, with Sewing at the helm since last year, has tried to revive Deutsche's fortunes, but problems have persisted.
In April the bank called off nearly six weeks of talks to merge with cross-town rival Commerzbank.
It then embarked on a plan for "tough cutbacks" to its investment bank, representing a major retreat from investment banking for Deutsche Bank, which for years had tried to compete as a major force on Wall Street.
As it reshapes, the bank now expects 2019 revenue to be lower than in 2018. The forecast marks a further scaling down in expectations from previous quarters.
Net revenue in the quarter fell 6pc to 6.2 billion euros. Analysts on average had expected 6.3 billion euros in revenue, according to a consensus forecast posted on the bank's website.
Revenue at Deutsche's cash-cow bond-trading division dropped 4pc in the quarter, while equities sales and trading revenue dived 32pc.
The declines underscore the continued weakness at the lender's investment bank, which saw an 18pc drop in net revenues during the period.
Details of those plans were announced earlier this month. They include plans to scrap its global equities business and scale back its investment bank. It also reshuffled management.
The bank will set up a new so-called "bad bank" to wind down unwanted assets, with a value of 74 billion euros of risk-weighted assets.
Reuters reported on Tuesday that it will take years to shed those unwanted assets, tying up capital that could have generated income of 500 million euros a year.
Some investors have told Reuters they doubted these moves would be enough to turn around its flagging fortunes in the face of intense competition and low interest rates.
Others investors have said they were worried Deutsche Bank would backtrack on a pledge not to tap shareholders for additional cash, particularly in view of its capital constraints.
"I really can't say that I see the positives in this plan. I remain a bitter curmudgeon," said Barrington Pitt-Miller, portfolio manager at Janus Henderson Investors.