The decision, announced by deputy governor Michael Atingi-Ego at a news conference, is the third time in a row the bank has kept its main policy rate unchanged.
Inflation fell to 9.0% year-on-year in March from 9.2% a month earlier.
Central banks all over Africa have had to walk the tightrope on interest rates vis-a-vis inflation, working to "cool" demands that have sent prices soaring while not choking off the economy to the point of recession.
