Both are expected to keep rates on hold on Thursday, but markets are waiting to see if ECB chief Jean-Claude Trichet uses the "strong vigilance" phrase to signal a next rate rise in June after the initial move in April.
Such a move would support the euro, the region's main reference currency, providing support for the local units.
"A (Czech) rate hike today would come as a big surprise which would likely cause EUR-CZK to drop sharply," Commerzbank said in a morning note.
"Unchanged rates might disappoint some market participants but crown weakness is likely to be limited," Commerzbank added.
The Czech central bank has kept its benchmark interest rate at an all-time low of 0.75 percent since the end of May 2010. The markets are pricing in a first rate hike in the Czech Republic within three months.
The Czech central bank is expected to publish its decision at 1100 GMT, while the ECB is to announce its call at 1145 GMT. Additionally, the Bank of England is also seen keeping rates unchanged, with a decision expected at 1100 GMT.
At 0749 GMT the crown added 0.1 percent versus the euro.
The forint gained 0.25 percent to the euro after Hungary sold seven-year euro bonds worth one billion euros on Wednesday, possibly completing its foreign currency debt financing goal for 2011.
Markets will focus on the government's bond auctions at 0930 GMT
At 1500 GMT Hungary's economy ministry will also publish preliminary cash-flow April budget data, after the deficit hit 108 percent of the full-year plan at the end of March.
The zloty recouped part its Wednesday losses, helped by the prospect of European Union funds being exchanged on the market by the Polish finance ministry and the approaching sale of Polkomtel, probably to foreign buyers.
"In place of our CZK trade we enter into a tactical long PLN versus EUR cash position (target 3.85, stop 4.00). Several factors should offer the PLN some support in the coming weeks," Barclays Capital said in a note on Wednesday evening.
"First, there is plenty of catch-up potential when comparing PLN year-to-date performance versus other CEE currencies. In addition, we expect privatisation/IPO flows to pick up in the second quarter relative to the first quarter."
Elsewhere, the Romanian leu was flat ahead of the finance ministry's tender of three-year treasury bonds worth 500 million lei ($180.9 million) later in the day.
Romania sold a more-than-planned 939 million euros ($1.4 billion) in three-year euro bonds on Wednesday at 4.9 percent, from 4.8 percent at a previous November tender.