Voting in the European election takes place on 4 June
Polling cards containing the wrong polling station information have been issued to 800 people in west Belfast.
Sinn Fein MLA Jennifer McCann said it was a "huge error" less than a week before the European Election.
She wants the chief electoral officer to give a public apology for the "debacle" and explain what happened.
The Electoral Office said it was sending letters to each individual apologising for the mistake and providing the correct details.
Ms McCann said she had been contacted by a number of constituents in the Poleglass area about the mistake.
''This is a huge error for the Electoral Office to make with less than a week to go before Election Day," she said.
''I am calling on the Electoral Office to immediately reissue polling cards to all the affected electors containing the correct information and to engage in an immediate pro-active publicity campaign to inform those affected by this grave error of where their polling station actually is.
''I am also calling on the chief electoral officer to give a public apology for this debacle and to provide a full explanation of what went wrong."
An Electoral Office spokesperson said: "It has been brought to our attention that approximately 800 electors in Poleglass have received poll cards with the name of the wrong polling station on it.
"Letters are being sent today by first class mail to each individual apologising for the error and providing the correct details together with a map showing the location of their correct polling station."