The agency said May saw a 0.3 percent rise for the non-food sector while fuel remained unchanged and sales in food, drinks and tobacco slipped 0.3 percent.
Annually, retail sales are 0.7 percent higher compared to the same time this year, largely driven by the 1 percent and 0.8 percent gains seen in non-food items and fuel respectively.
"It now looks most likely that euro zone retail sales volumes eked out only slight growth in the second quarter, which adds to the impression that the euro zone is finding it hard to build appreciable growth momentum," said chief U.K. and European economist at IHS Global Insight, Howard Archer.
Read MoreEurope stocks up; ECB, US payrolls ahead
"Flat retail sales in May, coupled with a modest dip in euro zone consumer confidence in June from May's 79-month high, reinforces suspicion that any improvement in euro zone consumer spending is more likely to be gradual than pronounced over the coming months - especially as there are still significant constraints on consumers in several countries," said Archer.
Euro zone unemployment was stable at 11.6 percent for the second consecutive month in May, down slightly from the 12 percent seen a year ago, according to Eurostat data released on Monday.
Follow us on Twitter: @CNBCWorld