And it pushed back against bets on cuts in the near future.
Calm inflation data over the last few months has all but ruled out further policy tightening.
It's led to a debate among economists on how the ECB will reverse course and lower rates.
However, ECB President Christine Lagarde didn't hint that policy easing was approaching, and instead kept guidance for steady rates ahead.
"We did not. We did not discuss rate cuts at all. No discuss, no debate on this issue."
Lagarde has been under pressure to defend or change her guidance that rates would stay where they are for the next few quarters.
Markets predict a first rate cut in the spring.
Pressure was also added when the U.S. Federal Reserve signalled late Wednesday (December 13) that lower borrowing costs would come next year.
After Thursday's decision, traders trimmed bets on ECB rate cuts, which are now seen starting in April.
In London, Britain's central bank also kept rates at the same level, which is currently at a 15-year high of 5.25%.
The Bank of England said British rates needed to stay high for "an extended period".
