"As regards bank profitability, ECB research finds little evidence that our monetary policy is currently doing harm," Draghi told an audience in Frankfurt.
The central bank has been under some criticism from bank managers for keeping interest rates too low for a long time. The lower that interest rates are, the less banks can charge customers for taking out loans. Many CEOs have therefore bemoaned the ultra-loose policy that the central bank has embarked upon.
"Net interest income has remained quite stable over the past two years," Draghi noted about the balance sheets of European banks.
"If there are any negative effects of low rates on net interest income in the future, they should be largely offset by the positive effects of monetary stimulus on the other main components of profitability, such as the quality of loans and therefore on loan-loss provisions," Draghi added.
Despite the improved economic situation in the euro zone, the central bank needs to be "patient" when normalizing monetary policy, Draghi also said during his speech on Friday.
"This is reflected in the monetary policy decisions that we took last month. These aim to signal our growing confidence in the euro area economy, while also acknowledging that we must be patient and persistent for inflation to return sustainably to our objective," Draghi said at a conference in Frankfurt.
The ECB announced in October that it will cut the level of bonds it purchases every month, starting in January, to 30 billion euros ($35 billion) from 60 billion euros. The central bank also said that it will extend its program until at least September next year. The ECB added at the time that it would adapt its policy as necessary depending on the trajectory of inflation.
The central bank has been buying bonds to help stimulate lending in the euro zone and boost growth.
Draghi reiterated Friday that its quantitative easing program could run beyond September of 2018, "if necessary, and in any case until we see a sustained adjustment in the path of inflation."
"Despite this progress on the real side of the economy, from a monetary policy perspective our task is not complete, as we have not yet seen a sustained adjustment in the path of inflation," Draghi told the audience.
Data out on Thursday confirmed that core inflation, excluding energy and food, hit 1.1 percent in October. The bank's aim is to push it closer to 2 percent.
In its latest forecasts, the ECB estimated a GDP (gross domestic product) rate of 2.2 percent for this year and 1.8 percent for next year and core inflation to reach 1.2 percent in 2017 and 1.3 percent in 2018. Though the bank is likely to raise such forecasts when it meets next month, inflation expectations remain far from the bank's objective.