Governor Jiri Rusnok was due to comment on the decision and present the board's assessment of risks to the CNB staff economic forecast at a news conference scheduled for 2.15 pm (1215 GMT).
All 13 respondents in a Reuters poll among economists had predicted the two-week repo rate to stay at 0.75 percent, where the central bank had raised it in February.
The central bank has tightened policy in three steps since last August after nearly five years of extremely loose conditions of rates near zero combined with interventions to weaken the Czech currency.
With a fast-growing economy and the EU's lowest unemployment rate pushing up wages and inflation, the Czech central bank is one of the few in Europe raising borrowing costs. Economic growth reached 5.2 percent year-on-year in the fourth quarter.
However, inflation has been slowing down since October, dropping to 1.8 percent year-on-year in February, below the central bank's 2-percent target level for the first time since November 2016.
The central bank's staff forecast sees the next rate hike only around the turn of the year and central bankers have said there was no rush with policy tightening, mainly due to the strengthening of the crown.
The crown has gained 6.1 percent against the euro since last April when the central bank dropped its intervention regime, contributing to tighter monetary conditions.
Rusnok said earlier this month another hike may come later this year if the situation requires it. But at the same time he said the next move may also only come around the turn of the year, or in 2019.
One factor holding the Czechs back has been the European Central Bank's continued loose policy delivered through asset purchases planned until at least September.